rapport d'activité lpc caen 2012 - 2013
TRANSCRIPT
2012 - 2013
RAPPORT D’ACTIVITÉ
2012 – 2013
Foreword
Nuclear Physics Research
Nuclear structure 2
Nuclear dynamics and thermodynamics 9
Theoretical physics and phenomenology 22
Interdisciplinary Research
Nuclear waste management 29
Medical and industrial applications 36
Group « Interactions Fondamentales et nature du Neutrino » (GRIFON)
Precise correlation measurements in nuclear beta decay 42
High resolution study of low energy charge exchange collisions with a MOT (magneto-optical trapped) target
44
Towards a new measurement of the neutron Electric Dipole Moment (EDM) 26
Search for neutrinoless double beta decay 48
Activités Techniques et Administratives
Service administratif 55
Bureau d’études et mécanique 56
Service électronique et microélectronique 59
Service informatique 66
Service instrumentation 69
Documentation 73
Qualité et soutien aux projets 74
Hygiène et sécurité 75
Diffusion du savoir
Enseignement 77
Formation par la recherche 78
Formation permanente 79
Valorisation 83
Actions de communication 84
Conférences et rencontres scientifiques 86
Informations générales
Personnels permanents 92
Organigramme 93
Chercheurs associés 94
Glossaire 95
CONTENTS
Le présent rapport d'activité couvre la période 2012-2013. Malgré une situation financière tendue, iltémoigne, nous l'espérons, du dynamisme des équipes de recherche avec le concours remarquable del'ensemble des services du Laboratoire. Malgré sa taille relativement modeste, le Laboratoire couvreun large ensemble de thématiques qui va de la recherche fondamentale à la rechercheinterdisciplinaire à vocation sociétale.
Sans être exhaustif, voici un bref résumé de nos activités sur la période considérée :
En physique nucléaire, l'équipe 'Dynamique et Thermodynamique' a poursuivi l'analyse descampagnes de mesures avec le détecteur INDRA portant sur l'étude des réactions nucléaires etprépare les tests sur faisceaux des premiers modules de FAZIA, le futur multidétecteur de particuleschargées. Le groupe "Structure" est engagé dans d'ambitieux programmes expérimentaux à RIKEN,au GANIL et à ISAC portant sur les noyaux exotiques riches en neutrons. Il prépare aussi uneprochaine expérience à ISOLDE.
En theorie et phénoménologie, le groupe a produit d'importants résultats dans les méthodes MonteCarlo quantiques et dans l'étude de l'équation d'état de la matière nucléaire dans les objets stellaires.
En ce qui concerne le groupe "Interactions Fondamentales et Nature du neutrino", l'expérience nEDMau PSI portant sur la mesure du moment électrique dipolaire du neutron est maintenant dans unephase de prise de données. En même temps, le groupe prépare la phase II de l'expérience. Laprésente période a vu l'achèvement et la finalisation de la prise de données sur NEMO3 au LSMdédiée à la recherche de l'émission double-beta sans neutrinos. Le groupe est maintenant largementimpliqué dans la construction du démonstrateur de SuperNEMO. Les expériences de recherche decourants exotiques dans la décroissance beta menèes au GANIL sont en phase d'analyse. De beauxrésultats ont été obtenus en collaboration avec des physiciens atomistes dans le domaine del'interaction ion-atome et dans l'étude du phénomène de shake-off.
Le groupe "Aval du Cycle" a poursuivi l'expérience GUINEVERRE du programme FREYA sur leréacteur sous-critique VENUS-F au SCK. Il prépare en même temps les expériences sur la future ligneNFS à SPIRAL2. L'équipe "Applications médicales et industrielles" mène ses recherches dans ledomaine de la hadronthérapie à travers les programmes France-Hadron et Rec-Hadron. Il participeactivement au projet ARCHADE et a aussi initié de très fructueuses collaborations avec le mondeindustriel.
FOREWORD
En dehors de l'appui aux projets des équipes de recherche, les services du Laboratoire sont engagésdans des développements propres. En particulier, le système d'acquisition FASTER a atteintmaintenant un niveau de maturité qui permet son déploiement sur nos expériences et dans denombreux projets en France et à l'étranger. Notre contribution au projet SPIRAL2 s'est poursuivie etaccrue avec notamment une importante contribution des membres de l'atelier au montage del'accélérateur. Le développement du RFQ pour SPIRAL2 poursuit son cours. Le savoir-faire acquis dansce domaine va permettre notre participation au développement de la ligne basse énergie de S3 etdans l'équipement du hall expérimental DESIR.
Le Laboratoire comporte une forte composante d'enseignants-chercheurs. Ces derniers ont la tâchedifficile de mener de front leur activité d'enseignement et de recherche. Leurs nombreuses prises deresponsabilité dans les formations et diplômes font du Laboratoire un acteur reconnu au sein del'Université de Caen Basse Normandie et de l'ENSICAEN. Depuis de nombreuses années, noussommes engagés dans de multiples actions de vulgarisation auprès des jeunes et du grand public.Cette activité s'est poursuivie à travers diverses manifestations et rencontres. A noter l'accueil d'unnombre de plus en plus grand de stagiaires de tout niveau de formation.
Certaines aspects primordiaux, non 'quantifiables', n'apparaissent pas à la lecture d'un tel rapport.D'abord l'engagement sans failles des personnels dans les projets du Laboratoire et ce, malgré desperspectives de carrière souvent difficiles. Ensuite, l'excellente ambiance de travail dans uneatmosphère conviviale et détendue. Enfin, à l'heure de la multiplication des sources de financement,le haut niveau de cohésion, de mutualisation et d'entraide entre les équipes et les services qui font duLaboratoire bien autre chose qu'un simple 'hôtel à projets'.
C'est un plaisir de remercier l'ensemble des personnes qui ont pris part à l'élaboration de ce rapport.Une mention particulière à Samuel Salvador pour la mise en œuvre de la partie scientifique età Sandrine Guesnon pour l'important travail de mise en forme de l'ensemble du document.
En vous souhaitant une bonne lecture,
Dominique DurandDirecteur du Laboratoire
Nuclear structure
Nuclear dynamics and thermodynamics
Theoretical physics and phenomenology
RESEARCH
NUCLEAR PHYSICS
1
Nuclear structure
The Nuclear Structure (or “Exotiques”) group is active in the investigation of the structure of neutron-rich nuclei using the probes of direct
reactions and decay spectroscopy.
In the direct reaction studies, the structure of light (A<50) neutron-rich nuclei, including haloes, clustering and correlations and shell structure,is explored using energetic radioactive beams. Two different approaches are employed: (i) at high energies (>100 MeV/nucleon) and close tothe dripline nucleon “knockout”, breakup, inelastic excitation and Coulomb dissociation; and (ii) at low energies (~5 – 10 MeV/nucleon) andcloser to stability nucleon transfer.
The high-energy reaction studies, which have been the main focus of the group’s reaction studies activities over the course of the last twoyears, are undertaken at the Radioactive Isotope Beam Factory (RIBF) at RIKEN where beam intensities 3 or 4 orders of magnitude higherthan elsewhere, are available for the light near dripline nuclei. At the RIBF experiments are carried out, with radioactive beams delivered bythe BigRIPS fragment separator, using the ZDS zero-degree spectrometer coupled to the DALI2 NaI array and, since Spring 2012, theSAMURAI spectrometer plus NEBULA neutron array. One of the goals of the group in the next few years is to upgrade, through a doubling ofthe number of scintillator walls, the NEBULA array (“NEBULA-Plus”) to enable us to exploit to the maximum the unique beams available atthe RIBF and to explore, in particular, multi-neutron decaying systems and the most exotic neutron-rich systems accessible. This project is, atthe time of writing, the subject of a grant request – “EXPAND” – made to the ANR.
Our complementary transfer reaction studies – typically neutron addition to the beam via (d,p) in inverse kinematics – at lower energies andcloser to stability employ at GANIL-SPIRAL1, the TiaRA Si-strip array coupled to the EXOGAM Ge-array and the VAMOS spectrometer. In thenear future experiments will be undertaken employing beams, such as 16C, not available with SPIRAL1, prepared using the LISE3 separator.In the case of our TRIUMF based work, the beams are delivered by the ISAC2 facility (which offers a suite of beams unavailable at SPIRAL1)and the SHARC Si-strip array coupled with the TIGRESS Ge-array is employed for the measurements. Owing to the lack of a suitablespectrometer, zero-degree detection is provided by a thin scintillator plus stopper foil setup developed at LPC. The main priority in the nearfuture at ISAC is the measurement of the d(28Mg,pγ)29Mg reaction which will complement our earlier work on d(24,26Ne,p)25,27Ne [1,2] andfurther help map the transition into the island of inversion around N=20.
The second main theme of the group’s research is centred on the investigation of structure through β-decay, and in the context of neutron-richnuclei, the study of β-delayed neutron emission. Presently this activity is focussed on R&D for a new neutron time-of-flight array which hasincluded extensive neutron beam measurements at CEA/DAM-Arpajon. In addition, a proof of principle experiment is under preparation forISOLDE aiming at a measurement of the β-delayed two-neutron decay of 11Li. Extensive source testing, in particular in terms of investigatingneutron-gamma discrimination techniques, digital signal processing and new scintillators, has also been carried out at LPC. This work hasbenefited greatly from the untiring support of our colleagues at LPC who have developed the FASTER digital acquisition system.
N.L. Achouri, F. Delaunay, S. Leblond*, J. Gibelin, F.M. Marqués, N.A. Orr, M. Pârlog, M. Sénoville*
Collaboration : D. Durand (LPCC), G. Lehaut (LPCC), M. Colonna (INFN Catania), H. Hamrita (IPN Orsay/CEA Saclay)
*PHD students
2
The measurements were accomplished using the SAMURAI
spectrometer [6] coupled to the large area neutron array NEBULA
[7] and were performed as part of the first phase of SAMURAI
experiments following the successful commissioning in Spring
2012. The analysis to date has concentrated on the
fragment+neutron channels and, in particular, 17B+n which is
known to exhibit a strongly interacting virtual s-wave threshold state
[8]. Beyond the intrinsic physics interest noted above, a well
defined threshold state provides an ideal means to validate the
calibration and analysis procedures.
In addition to accessing 18B via proton removal from 19C, which
should populate almost exclusively s-wave strength, the
complementary probe of neutron removal from a 19B beam has
been investigated. Fig. 1 shows the reconstructed 17B+n invariant
mass (or relative energy) spectra for the two reactions which were
undertaken at around 240 MeV/nucleon. As may be clearly seen
the proton removal populates a very narrow threshold structure, the
form of which is consistent with the strongly interacting s-wave
virtual state deduced by Spyrou et al. [8]. The neutron removal,
however, in addition to the threshold peak, shows clear evidence
for the population of a state or states in the region of 0.5–1 MeV.
The further analysis of these preliminary results is currently
underway, including two-proton removal from 20N, which is
expected to populate preferentially d-wave strength in 18B. The
analysis of the data sets for the analogue reactions populating21C – C(22C,20C+n), C(22N,20C+n) and C(23O,20C+n) – are also in
progress.
The work outlined here forms part of the PhD thesis of S. Leblond
who acknowledges the support provided in terms of a 6 month
RIKEN Nishina Center International Program Associate fellowship
in 2013.
Structure at and beyond the neutron dripline:18,19B and 21,22C
Collaboration: Tokyo Institute of Technology (Japan), RIKEN (Japan) and the SAMURAI Collaboration
Fig. 1: Preliminary results for the 17B+n relative energy spectra obtained for proton and neutron removal reactions at 240 MeV/nucleon.
ANIME: a simulation code for NEBULA
Collaboration: Tokyo Institute of Technology (Japan)
As noted in the overview to our group’s activities, our experimental program at RIKEN, which aims to explore the neutron
dripline and beyond, relies on the coincident detection of charged fragments using the SAMURAI spectrometer and beam
velocity neutrons (E~250 MeV) with the NEBULA multi-element plastic scintillator array. The response of the neutron array is a
key element in the analysis of these experiments. There are two existing approaches for the description of this response: 1)
GEANT4, that uses intra-nuclear cascade models; 2) MENATE, that describes individually all possible reaction channels on H
and C. The former, however, functions very much as a “black box” which is difficult to modify if discrepancies with the data
appear, while the latter was developed for energies well below 100 MeV, and for the specific setup of cylinders as for the
DEMON array.
The investigation of the light neutron-rich dripline nuclei, including in particular those exhibiting haloes, is a central theme of
nuclear structure physics. In the present work a series of measurements, aimed at elucidating the structure of the two heaviest
candidate two-neutron halo systems, 19B and 22C [3-5], and the associated unbound sub-systems 18B and 21C, the level schemes
of which are critical to the defining the 17B-n and 20C-n interactions for three-body models, have been undertaken. In addition to
being of direct importance to halo physics, 18,19B and 21,22C are of considerable interest in terms of the evolution of shell-structure
far from stability as they span the N=14 and 16 sub-shell closures below doubly-magic 22,24O.
3
The reaction kinematics are treated as quasi-free scattering on
n/p/α inside C, taking into account the corresponding separation
energies and intrinsic momentum distributions. The outgoing
neutron angular distribution is calculated from the
phenomenological parameterization of the DEMONS code for the
scattering off nucleons [9], and as an energy-dependent
exponential in cosθ for the other channels. The recoiling protons
are tracked as they move through the array with the same
geometrical interface as the neutrons, and the energy deposited
by all charged particles is transformed into light and propagated to
the two photomultipliers coupled to each bar.
We have checked the performance of ANIME with data acquired
during the commissioning of SAMURAI+NEBULA using the7Li(p,n) reaction. As an example, Fig. 2 shows the light output
recorded in NEBULA from mono-energetic neutrons at 250 MeV.
The agreement is as good at 200 MeV, as well as for the
multiplicity of the number of individual bars hit and the relative
angle between them. The latter is essential in order to understand
cross-talk in the array – that is, the interaction of one neutron at
several points within NEBULA that may mimic the detection of
several neutrons. ANIME will be employed in constructing a
cross-talk filter for the analysis of reaction channels with more
than one neutron in the final state, as well as in our planned
extension of NEBULA to 4 walls.
Fig. 2: Light output, Q (MeVee), for 250 MeV neutrons interacting with the NEBULA array. The data are compared with the results obtained using the ANIME code (dashed line). The contributions of individual
reaction channels are shown.
R&D for a new time-of-flight neutron array
Collaboration: CIEMAT-Madrid (Spain), CEA-DIF Bruyères-le-Châtel
Owing to the large Qβ values and the low neutron binding energies of the daughter nuclei, the β-decay of very neutron-
rich nuclei is often followed by the emission of neutrons from unbound states. The detection of such relatively low-energy
neutrons (<5 MeV) is therefore crucial to constructing complete decay-schemes. In order to improve the detection performance
and, in particular, provide for a multi-neutron detection capability, a new modular time-of-flight array based on discriminating
scintillators and coupled to a digital data acquisition system is being developed by our group.
Existing neutron arrays based on large plastic scintillator bars, such as the TONNERRE array [10], present limitations. First,
owing to the absence of pulse-shape discrimination, the time-of-flight spectra are contaminated by a background arising from
the ambient γ-rays and cosmic muons, which renders the identification and measurement of weak neutron transition delicate.
Furthermore, two-neutron detection is extremely difficult as multiplicity-two events are dominated by random coincidences
involving γ and cosmic rays. In addition, TONNERRE suffers from a limited energy resolution, asymmetric lineshapes and a
relatively high neutron energy threshold (~300 keV).
The following strategies, as described in earlier reports, have been adopted to overcome these limitations. These include, in
particular:
Limited scintillator volumes viewed by large-diameter photomultiplier tubes and digital signal processing to lower
the threshold and reduce the lineshape asymmetry.
Relatively thin detectors at increased distances (>2 m) to improve the energy resolution.
To allow for multi-neutron detection by reducing the background with pulse shape discrimination, using liquid
scintillators or discriminating solid organic scintillators.
A modular array with variable geometry to limit cross-talk and optimise cross-talk rejection schemes.
In the present work, we have opted for a third approach: the development from scratch of a new code ANIME (“Algorithms forNeutron Identification in Modular Experiments”), that treats the individual reaction channels at higher energy in a relatively
simple manner, with a more user-friendly geometrical interface. NEBULA consists of multiple planes of vertical plastic
scintillator bars, in which neutrons are tracked until they interact with either H or C. The interaction probability for each reaction
channel is calculated using the MENATE_R database, which has been extended beyond 100 MeV.
4
Fig. 3: Intrinsic detection efficiency as a function of the neutron energy. The measurements (squares) are compared to simulations (solid and dashed lines) for two different thresholds.
An example of the results obtained for the efficiency measurements are shown in Fig. 3. As may be seen, simulations
employing the MENATE code [12] and a revised version of MENATE developed for use within GEANT4, predict efficiencies in
good agreement with the data.
In terms of the cross-talk measurements, the setup employed is illustrated schematically in Fig. 4 whereby neutrons scattered
from the unshielded module [A] to the shielded one [B] were measured for different relative positions of the two modules. Fig. 5
displays, for 2 MeV incident neutrons, the time-of-flight measured between the two detectors for events identified as neutrons.
Also shown are the results of a MENATE based simulation incorporating only the active volume of each detector. Reasonable
agreement was obtained between the experimental and simulated cross-talk probabilities for the full range of incident neutron
energies (1–15 MeV) and detector relative positions (θAB≈40–90°). The next step that will be undertaken will be to test the
efficacy of cross-talk filters on these data, and perform more realistic simulations including the inactive materials such as the
detector housing.
Fig. 4: Schematic view of the detector configuration used for the cross-talk measurements.
The module design that has been adopted is based on a BC501 liquid scintillator cell with a diameter of 20 cm and a depth of
5 cm, viewed by a 13 cm photomultiplier tube through a light guide. The design was characterised in a series of measurements
undertaken using monoenergetic neutron beams at the CEA-DIF Bruyères-le-Châtel facility and the FASTER digital acquisition
developed here at LPC. Intrinsic efficiencies and cross-talk probabilities were measured at several neutron energies in the
range of interest (1–15 MeV) in order to validate the simulations and the kinematical cross-talk filters developed for higher
energies [11]. These data are the first measurements of cross-talk probabilities below 14 MeV neutrons energy.
5
Fig. 5: Time-of-flight between detectors A and B (see Fig. 2) for events identified as a neutron in both detectors, measured with 2 MeV neutrons (blue spectra) for three
different angles (qAB) and an analysis threshold of 100 keVee. The results of a simulation including only the active volumes are shown by the red spectra.
A proof-of-principle experiment accepted at the ISOLDE facility
at CERN is envisaged to be run in the near future. The principal
goal of this experiment will be the detection of two β-delayed
neutrons in coincidence (from the decay of 11Li which has the
highest presently known two-neutron emission probability) and,
for the first time, the measurement of their energies and angular
correlations. The coincident detection of two neutrons is
currently being tested using a 252Cf source with some 10
neutron detectors, an LaBr3 scintillator for the time-of-flight start
and elements of the FASTER digital acquisition system.
In order to investigate the possible utility of a reduced scintillator
volume on the neutron-γ discrimination at low energy and to
explore scintillators other than the usual liquids, we have
undertaken a series of measurements to characterise small
cylindrical (5 cm diameter × 5 cm thick) samples of organic
scintillators: crystals (p-terphenyl, trans-stilbene), liquid
scintillators (BC501A and NE213 for reference purposes,
deuterated BC537) and discriminating plastics (EJ-299-33,
CP197 from CEA/LCAE). Whereas the crystals show a light
yield twice as large as that of the usual liquids, their
discrimination performance is not significantly better. In
particular, the neutron-γ separation obtained at low energy with
liquids and the p-terphenyl crystal are similar. The currently
available discriminating plastic scintillators cannot compete with
the liquids and the crystals in terms of discrimination. The
deuterated BC537 liquid scintillator exhibits a smaller light yield
and a poorer quality discrimination as compared to
BC501A/NE213, and therefore is not a viable alternative.
Finally, it is worthwhile noting that reducing the diameter of the
liquid scintillator cell from 20 cm (see above) to 5 cm provides
for a lowering of a factor of two of the threshold at which
neutrons can be unambiguously identified.
The work presented here forms part of the PhD thesis of M.
Senoville [13].
Investigation of the compressions modes in unstable Nickel isotopes
Collaboration: GANIL, IPN Orsay, ATOMKI (Hungary), KU Leuven (Belgium), Konan University (Japan), KVI Groningen (Netherlands), MSU (USA), Notre Dame (USA), RNCP (Japan), RIKEN (Japan), USC (Spain)
The study of collective excitation modes, such as the Isoscalar Giant Monopole (ISGMR) and Dipole (ISGDR) resonances,
has been pursued in stable nuclei over much of the last three decades with the aim of determining the incompressibility (K) of
nuclear matter [14]. This fundamental property is of significant importance as it dictates the excitation energies of the
compression modes and, in terms of the equation of state, it plays a crucial role in describing nuclear collisions and supernovae
resulting from the collapse of very heavy stars. Through extensive experimental and theoretical studies, the incompressibility,
K, has been relatively well determined in stable nuclei. The asymmetry term in the expansion of K, however, has been poorly
determined, since it requires the investigation of compression modes over a broad isotopic chain. In addition, in exotic nuclei
new phenomena are expected to occur, such as pygmy resonances with multipole strengths reflecting the collectivity arising
from the neutron or proton-skins relative to the core.
With this goal in mind, and following the first successful measurement of the ISGMR and ISGQR in 56Ni [15], two experiments
have been performed at GANIL using secondary beams produced with the LISE3 separator: a search for the ISGDR in 56Ni and
the measurement of the ISGMR and ISGQR in 68Ni. The three measurements employed the MAYA active target filled either
with deuterium or helium (+quencher) gases following the tests described in Ref. [16].
6
The 68Ni experiment employed a 50 MeV/nucleon beam of
intensity 104 pps on both deuterium and helium gas targets.
Excitation energy spectra deduced for the α(68Ni,α)68Ni* reaction
are shown in Fig. 6. The GMR was determined to lie at
21.7±1.9 MeV and evidence for a soft monopole mode,
predicted but never observed, was found at 13.2±0.5 MeV. The
corresponding angular distributions, analysed using Distorted
Wave Born Approximation with Random Phase Approximation
transition densities, indicate that the GMR exhausts a large
fraction of the energy-weighted sum rule and that neutrons
mainly contribute to the soft monopole mode. Both experiments
using deuterium and helium gas provided coherent results
providing added confidence in or conclusions and demonstrating
the relevance of alpha inelastic scattering in inverse kinematics
in order to probe both the GMR and soft modes in neutron-rich
nuclei. This work formed part of the PhD of M. Vandebrouck [17]
and a manuscript has been submitted for publication in Physical
Review Letters.
The analysis of the inelastic scattering of 56Ni on helium is
currently ongoing in order to locate the ISGDR of 56Ni. The
excitation energy spectrum for 56Ni has been reconstructed and
simulations have been performed to estimate the angular
acceptances and the efficiency of the reconstruction. In order to
refine our understanding of the setup, the angular distribution for
the elastic scattering of 56Ni on helium has been derived and a
preliminary result is shown in Fig. 7. We note that the minimum
in the cross-section is a slightly shifted compared to DWBA
predictions and the origins of this discrepancy are now being
investigated. This work forms part of the PhD of S. Bagchi
(University of Groningen).
Finally, we note that the 56Ni + He data is also being exploited in
order to explore the cluster nature of 56Ni [18].
Fig. 6: Excitation energy spectrum for the α(68Ni,α)68Ni* reaction for a) all measured angles and b) for θCM=5.5°. In both cases data are fitted with
Lorentzian distributions centred at 13.2 (red), 15.7 (blue) and 21.7 MeV (red lines) corresponding to the soft GMR, GQR and GMR, respectively. The
broad peak above 25 MeV (dotted line) corresponds to several additional multi-polarities such as L = 1,3.
Fig. 7: Differential angular distribution for the elastic scattering of 56Ni on helium. The dashed line is the result of a DWBA calculation.
7
Publications
The N = 16 spherical shell closure in 24OTshoo K., Satou Y., Bhang H., Choi S., Nakamura T. et al.Physical Review Letters 109 (2012) 022501
Search for Superscreening effect in SuperconductorUjic P., de Oliveira Santos F., Lewitowicz M., Achouri N.L., AssiéM. et al.Physical Review Letters 110 (2013) 032501
Structure of unbound neutron-rich 9He studied using single-neutron transferAl Kalanee T., Gibelin J., Roussel-Chomaz P., Keeley N., BeaumelD. et al.Physical Review C 88 (2013) 034301
Limited Asymmetry Dependence of Correlations from Single Nucleon TransferFlavigny F., Gillibert A., Nalpas L., Obertelli A., Keeley N. et al.Physical Review Letters 110 (2013) 122503
Core excitations and narrow states beyond the proton dripline: The exotic nucleus 21AlTimofeyuk N.K., Fernández-Domínguez B., Descouvemont P., Catford W.N., Delaunay F. et al.Physical Review C 86 (2012) 034305
Well-developed deformation in 42SiTakeuchi S., Matsushita M., Aoi N., Doornenbal P., Li K. et al.Physical Review Letters 109 (2012) 182501
Comment on "First Observation of Ground State DineutronDecay: 16Be"Marqués F.M., Orr N.A., Achouri N.L., Delaunay F., Gibelin J.Physical Review Letters 109 (2012) 239201
Spectroscopy of 18Na: Bridging the two-proton radioactivity of 19MgAssié M., Santos F. D. O., Davinson T., De Grancey F., AchouriN.L. et al.Physics Letters B 712 (2012) 198-202
β-delayed neutron emission studiesGómez-Hornillos M.B., Rissanen J., Taín J.L., Algora A., Kratz K.L. et al.Hyperfine Interactions 223 (2012) 185-194
Low-lying neutron f p-shell intruder states in 27NeBrown S.M., Catford W.N., Thomas J.S., Fernandez-Dominguez B., Orr N.A. et al.Physical Review C 85 (2012) 011302
Resonances in 19Ne with relevance to the astrophysicallyimportant 18F(p,(\alpha))15O reactionMountford D.J., Murphy A. S. J., Achouri N.L., Angulo C., Brown J.R. et al.Physical Review C 85 (2012) 022801
Direct mass measurements of 19B, 22C, 29F, 31Ne, 34Na and otherlight exotic nucleiGaudefroy L., Mittig W., Orr N.A., Varet S., Chartier M. et al.Physical Review Letters 109 (2012) 202503
Electrostatic mask for active targetsPancin J., Gibelin J., Goth M., Gangnant P., Libin J.F. et al.Journal of Instrumentation 7 (2012) P01006
In-beam spectroscopic studies of 44S nucleusCaceres L., Sohler D., Grévy S., Sorlin O., Dombradi Z. et al.Physical Review C 85 (2012) 024311
One-proton breakup of 24Si and the 23Al( p, γ )24Si reaction in type I x-ray burstsBanu A., Carstoiu F., Achouri N.L., Catford W.N., Chartier M. et al.Physical Review C 86 (2012) 015806
Resonances in 11C observed in the 4He(7Be,α)7Be and 4He(7Be,p)10B reactionsFreer M., Achouri N.L., Angulo C., Ashwood N.I., Bardayan D.W. et al.Physical Review C 85 (2012) 014304
One and two neutron removal reactions from the most neutron-rich carbon isotopesKobayashi N., Nakamura T., Tostevin J.A., Kondo Y., Aoi N. et al.Physical Review C 86 (2012) 054604
Publications
The N = 16 spherical shell closure in 24OTshoo K., Satou Y., Bhang H., Choi S., Nakamura T. et al.Physical Review Letters 109 (2012) 022501
Search for Superscreening effect in SuperconductorUjic P., de Oliveira Santos F., Lewitowicz M., Achouri N.L., AssiéM. et al.Physical Review Letters 110 (2013) 032501
Structure of unbound neutron-rich 9He studied using single-neutron transferAl Kalanee T., Gibelin J., Roussel-Chomaz P., Keeley N., BeaumelD. et al.Physical Review C 88 (2013) 034301
Limited Asymmetry Dependence of Correlations from Single Nucleon TransferFlavigny F., Gillibert A., Nalpas L., Obertelli A., Keeley N. et al.Physical Review Letters 110 (2013) 122503
Core excitations and narrow states beyond the proton dripline: The exotic nucleus 21AlTimofeyuk N.K., Fernández-Domínguez B., Descouvemont P., Catford W.N., Delaunay F. et al.Physical Review C 86 (2012) 034305
Well-developed deformation in 42SiTakeuchi S., Matsushita M., Aoi N., Doornenbal P., Li K. et al.Physical Review Letters 109 (2012) 182501
Comment on "First Observation of Ground State DineutronDecay: 16Be"Marqués F.M., Orr N.A., Achouri N.L., Delaunay F., Gibelin J.Physical Review Letters 109 (2012) 239201
Spectroscopy of 18Na: Bridging the two-proton radioactivity of 19MgAssié M., Santos F. D. O., Davinson T., De Grancey F., AchouriN.L. et al.Physics Letters B 712 (2012) 198-202
β-delayed neutron emission studiesGómez-Hornillos M.B., Rissanen J., Taín J.L., Algora A., Kratz K.L. et al.Hyperfine Interactions 223 (2012) 185-194
Low-lying neutron f p-shell intruder states in 27NeBrown S.M., Catford W.N., Thomas J.S., Fernandez-Dominguez B., Orr N.A. et al.Physical Review C 85 (2012) 011302
Resonances in 19Ne with relevance to the astrophysicallyimportant 18F(p,(\alpha))15O reactionMountford D.J., Murphy A. S. J., Achouri N.L., Angulo C., Brown J.R. et al.Physical Review C 85 (2012) 022801
Direct mass measurements of 19B, 22C, 29F, 31Ne, 34Na and otherlight exotic nucleiGaudefroy L., Mittig W., Orr N.A., Varet S., Chartier M. et al.Physical Review Letters 109 (2012) 202503
Electrostatic mask for active targetsPancin J., Gibelin J., Goth M., Gangnant P., Libin J.F. et al.Journal of Instrumentation 7 (2012) P01006
In-beam spectroscopic studies of 44S nucleusCaceres L., Sohler D., Grévy S., Sorlin O., Dombradi Z. et al.Physical Review C 85 (2012) 024311
One-proton breakup of 24Si and the 23Al( p, γ )24Si reaction in type I x-ray burstsBanu A., Carstoiu F., Achouri N.L., Catford W.N., Chartier M. et al.Physical Review C 86 (2012) 015806
Resonances in 11C observed in the 4He(7Be,α)7Be and 4He(7Be,p)10B reactionsFreer M., Achouri N.L., Angulo C., Ashwood N.I., Bardayan D.W. et al.Physical Review C 85 (2012) 014304
One and two neutron removal reactions from the most neutron-rich carbon isotopesKobayashi N., Nakamura T., Tostevin J.A., Kondo Y., Aoi N. et al.Physical Review C 86 (2012) 054604
References
[1] W.N. Catford et al., Phys. Rev. Lett. 104 (2010) 192501[2] S. Brown et al., Phys. Rev. C85 (2012) 011302(R)[3] K. Tanaka et al., Phys. Rev. Lett. 104 (2010) 062701[4] N. Kobayashi et al., Phys. Rev. C83 (2012) 054604.[5] L. Gaudefroy et al., Phys. Rev. Lett. 109 (2012) 20503.[6] T. Kobayashi et al., Nucl. Instr. Meth. B317 (2013) 294.[7] Y. Kondo et al., RIKEN Accel. Prog. Rep. 45 (2012) 131; http://be.nucl.ap.titech.ac.jp/~nebula[8] A. Spyrou et al., Phys. Lett. B 683 (2010) 129.[9] W.C. Sailor et al., Nucl. Inst. Meth. 277 (1989) 599.[10] A. Buta et al., Nucl. Instr. and Meth. A455 (2000) 412.
[11] F. M. Marqués et al., Nucl. Inst. Meth. A450 (2000) 109.[12] P. Désesquelles et al., Nucl. Inst. Meth. A307 (1991) 366.[13] M. Senoville, “Développement d’un nouveau multi-détecteur de neutron”, Thèse, Université de Caen Basse-Normandie (2013)[14] M. N. Harakeh and A. van der Woude, “Giant Resonances: Fundamental High-Frequency Modes of Nuclear Excitation”, Oxford University Press, Oxford, 2001.[15] C. Monrozeau et al., Phys. Rev. Lett. 100 (2008) 042501.[16] J. Pancin et al. JINST 7 (2012) 01006.[17] M. Vandebrouck, “Première mesure des résonances géantes isoscalaires dans un noyau exotique riche en neutrons : le 68Ni avec la cible active Maya”, Thèse, Université Paris Sud – Paris XI (2013) http://tel.archives-ouvertes.fr/tel-00872712.[18] H. Akimune et al. J. Phys.: Conf. Series 436 (2013) 012010.
References
[1] W.N. Catford et al., Phys. Rev. Lett. 104 (2010) 192501[2] S. Brown et al., Phys. Rev. C85 (2012) 011302(R)[3] K. Tanaka et al., Phys. Rev. Lett. 104 (2010) 062701[4] N. Kobayashi et al., Phys. Rev. C83 (2012) 054604.[5] L. Gaudefroy et al., Phys. Rev. Lett. 109 (2012) 20503.[6] T. Kobayashi et al., Nucl. Instr. Meth. B317 (2013) 294.[7] Y. Kondo et al., RIKEN Accel. Prog. Rep. 45 (2012) 131; http://be.nucl.ap.titech.ac.jp/~nebula[8] A. Spyrou et al., Phys. Lett. B 683 (2010) 129.[9] W.C. Sailor et al., Nucl. Inst. Meth. 277 (1989) 599.[10] A. Buta et al., Nucl. Instr. and Meth. A455 (2000) 412.
[11] F. M. Marqués et al., Nucl. Inst. Meth. A450 (2000) 109.[12] P. Désesquelles et al., Nucl. Inst. Meth. A307 (1991) 366.[13] M. Senoville, “Développement d’un nouveau multi-détecteur de neutron”, Thèse, Université de Caen Basse-Normandie (2013)[14] M. N. Harakeh and A. van der Woude, “Giant Resonances: Fundamental High-Frequency Modes of Nuclear Excitation”, Oxford University Press, Oxford, 2001.[15] C. Monrozeau et al., Phys. Rev. Lett. 100 (2008) 042501.[16] J. Pancin et al. JINST 7 (2012) 01006.[17] M. Vandebrouck, “Première mesure des résonances géantes isoscalaires dans un noyau exotique riche en neutrons : le 68Ni avec la cible active Maya”, Thèse, Université Paris Sud – Paris XI (2013) http://tel.archives-ouvertes.fr/tel-00872712.[18] H. Akimune et al. J. Phys.: Conf. Series 436 (2013) 012010.
8
Nuclear dynamics and thermodynamics(INDRAFAZIA collaborations)
The determination of the nuclear equation of state (EOS) is one of the key issue concerning Nuclear Physics. The
characterisation of its dependence in term of density, temperature and isospin are mandatory to describe accurately as wellheavy-ion collisions and properties of neutron stars. The EOS can be seen as the macroscopic consequence of the propertiesconcerning the underlying nucleon-nucleon (NN) interaction in nuclear matter. Studying the EOS is then directly related to thestudy of NN interaction, namely its density dependence via many-body correlations, and its isovector properties via the symmetryterm of EOS. In order to probe these features, we currently use heavy ion induced reactions in the Fermi energy domain andperform exclusive measurements using the 4π array INDRA. This allows to access to the dynamical (transport properties) andthe thermodynamical features of hot and compressed nuclear matter. INDRA is a international collaboration grouping 5institutes : GANIL Caen, IPN Orsay, LPC Caen, Laval University (Québec) and INFN Napoli (Italy). INDRA is in operation since1993 and 8 large data takings (campaigns) have been performed at GANIL (stable beams + SPIRAL1/CIME beams) in Franceand GSI in Germany. The collaboration is composed by 18 physicists + 3 PHD + 1 post-doc (2013) and still continue tomaintain INDRA in order to be ready for SPIRAL2 and GANIL beams in a near future. The collaboration is also deeply involvedsince 10 years on the next-generation 4π array; it is the FAZIA project. Taking advantage from the experience concerning 4πarrays, we are currently developping a new prototype of 4π detector and are in the present time in phase 2 of the FAZIAprogram. This phase consists in building a fully operational demonstrator, composed of 12 blocks made of 16 identificationtelescopes Si-Si-CsI with their embedded digital electronics.
Several research topics have been developped in the laboratory concerning the study of the dynamical and thermodynamicalproperties of nuclei with INDRA as well as instrumental developments for FAZIA. In section 1, we present an analysis concerningthe study of transport properties in nuclear matter and the determination of some fundamental in-medium quantities such asthe nucleon-nucleon mean free path and cross section. In section 2, we address temperature and excitation energymeasurements from an experimental point of view; indeed, these observables are at the centre of any thermodynamical studyand therefore also for the accurate determination of the nuclear EOS. In section 3, we present a recent experimental workconcerning the evaluation of the symmetry energy term on the nuclear EOS. In section 4, we show an experimental programaiming at the evaluation of the best Pulse Shape Analysis which can be achieved with highly homogeneous silicon detectors forthe FAZIA project. At last, Section 5 is devoted to the modelization of current signals produced in Silicon detectors, in order tooptimize the Pulse Shape Analysis for FAZIA.
L. Augey*1, R. Bougault, M. Kabtoul*2, E. Legouée*3, N. Le Neindre, O. Lopez, M. Parlog, E. Vient
Collaboration : D. Durand (LPCC), G. Lehaut (LPCC), M. Colonna (INFN Catania), H. Hamrita (IPN Orsay/CEA Saclay)
*PHD students1 since october 2013, 2 until july 2013, 3 until october 2013
9
Transport properties are critical in the description of the supernova collapse and the formation of a neutron star [1].
They are also one of the fundamental ingredients for microscopic models [2] and contribute for the determination of the
equation of state via the underlying in-medium properties of the nuclear interaction. Transport properties of nuclear matter are
probed with heavy-ion induced collisions (HIC) by looking at dissipation phenomena in term of energy and isospin diffusion. In
the Fermi energy domain, transport features should exhibit the interplay between Mean-Field (nucleus) and individual
(nucleons) effects, especially when looking at the energy dissipation reached in central collisions where the overlap between
the two incoming partners becomes maximal [3]. Fig. 1 displays the mean isotropy ratio RE [3] as a function of the incident
energy for 6 different symmetric systems ; this compilation consists in 40 experimental determination and illustrates the large
body of data available with INDRA. In this study, we have selected central collisions by using the total charge multiplicity as
detailed in [3,4]. The data are compared to the expected RE values for full transparency (blue curve) and full stopping (red
curve). In a simple picture for the central collisions consisting in 2 separate Fermi spheres with relative momentum given by:
Prel=αPrel0, where Prel
0 is the relative momentum according to the incident (relative) energy between the 2 incoming nuclei of
the reaction. The above-mentioned situations correspond then to α=0 for full stopping and α=1 for full transparency.
From the isotropy ratio, we evaluate the stopping ratio reached in such central collisions. This latter is computed as the
reduced distance d=(RE-RE(α=0))/(RE(α=1)-RE(a=0)) between the 2 extreme scenarii. It is instructive to note that the quantity
d2/3 can be nicely scaled as a function of the characteristic size of the system A1/3 as shown in [4]. This scaling suggests that
the stopping ratio, measured by d2/3, is related to the size of the system; in a Glauber scenario, the stopping is indeed related
to the in-medium NN cross section σNN and the average distance crossed by the scattered nucleons. Therefore, one can use
d as an estimate of the NN mean free path λNN or the associated cross section σNN related by the simple formula obtained
from kinetic theory: λNN≈1/ρσNN. This is done in Fig. 2 where we plot the estimated λNN from the simple formula: λNN ≈ R/d2/3,with R=r0A
1/3 and r0=1.25 fm.
In-medium effects in nuclear matter in the Fermi energy range
collaboration with D. Durand and G. Lehaut
Fig. 1: Mean isotropy ratio RE for protons as a function of incident energy in central collisions. The symbols correspond to different symmetric systems. The blue and red curves are the theoretical predictions for full transparency (blue) and full stopping
(red) respectively. From [4].
10
Fig. 2: In-medium mean free path λNN as a function of the incident energy. From [4].
We obtain the incident energy dependence concerning the in-medium mean free path λNN. We see that λNN is maximal around
Einc/A=40 MeV with a typical value λNN=8-9 fm. The decrease observed at lower incident energy is not commented here since
we believe that the reduced distance d is not valid when the Mean-Field dissipation is present; in this case, one has to evaluate
properly the dissipation reached in central collisions, due to the 1-body dissipation term (friction). At variance, for incident
energies larger than 40 A·MeV, we consider the sudden approximation used as a reference for full transparency to be valid.
Within this energy range, we observe a clear decrease for λNN, from 8-9 fm at 40 A·MeV toward a saturation around 4-5 fm at
100 A·MeV. This latter result is in full agreement with both theoretical and experimental values around and above 100 A·MeV[5,6,7].
To evaluate the magnitude of the in-medium effects, we then compare the NN cross section σNN obtained from the λNN values
displayed by Fig. 2. We take into account the important effect due to the quantum nature of the nucleons (Pauli exclusion
principle) as recommended in [8]. We obtain the reduction factors shown by Fig. 3.
The reduction factors are found to be quite large, ranging from 20% to 40%, indicating that in this incident energy range (40-100 A·MeV), the in-medium effects are far from being negligible and thus should be taken properly into account in any
microscopic descriptions such as transport models. The best agreement is found with the phenomenological prescription
proposed in [9] by Danielewicz [10]. It is also worthwhile to note that almost all prescriptions seem to converge toward the same
value above 100 A·MeV.
Fig. 3: In-medium reduction factor for the in-medium NN cross section. The curves correspond to different parametrizations used in recent theoretical descriptions. From [4].
11
Isospin transport during collisions around Fermi energy
A previous study [11] allowed us to develop an experimental method giving the probability for a particle to be emitted by
a hot Quasi-Projectile (QP), during a nuclear reaction around the Fermi energy. We decided to use this information to
determine the probability for a particle of not being evaporated. Knowing this last probability, we can then characterize an
eventual pre-equilibrium component or a neck emission, when this contribution exists. For two main reasons, the only way to
make this work, is to observe symmetric or quasi-symmetric collisions. Firstly, there are principally binary collisions for these
systems. Secondly, for obvious reasons of symmetry, the Quasi-Target (QT) should have the same physical behavior than
the Quasi-Projectile, consequently the same probability of evaporating a given particle. This study has been done for
different nuclear systems studied by the INDRA collaboration in the framework of a PhD [12]. We have wanted also to
confirm experimentally the validity of hypotheses done to determine these different contributions and to show the effective
quality of this method of isolation. The tool to attain this goal is to study the isospin diffusion and the isospin layout in the
velocity space, during a nuclear reaction, for the first time at two dimensions. The INDRA Collaboration has studied during its
fifth campaign the quasi-symmetric system Xe+Sn at 32 A·MeV using several isotopes of these both nuclei. It has thus used
four isotopic combinations:
Neutron Rich System [NN]
Proton Rich System [PP]
Mixed System with Proton rich projectile and Neutron rich target [PN]
Mixed System with Neutron rich projectile and Proton rich target [NP]
To study the way in which the densities of neutrons and protons during a nuclear reaction are distributed in the velocity
space (defined in the c.m.), respectively along the parallel and the perpendicular axis to the beam, we have defined Rami's
ratios [13] for different elementary squares in this space. These ratios are determined from ratios of ratios of different
isotopes as proton/deuteron obtained for the different considered isotopic configurations of collisions [13]. The ratio is
normalized to 1 for a neutron rich zone and to -1 for proton rich zone. The ratio is equal to 0 if there is an equilibration of
isospin.
For a specific selection of Quasi-Projectiles (angles defined in the laboratory frame between 4° and 6° and velocity between
0.1c and 0.12c, in the c.m. frame), we present, in Fig. 4, for the system 124Xe+124Sn at 32 A·MeV, the Rami's ratios (obtained
with protons/tritons) as a function of the perpendicular and parallel velocities in the c.m. frame. We have kept events with a
QP detected on one side of the beam. The perpendicular component of particles is negative if the particle is at the opposite
side of the QP.
Thermometry and calorimetry studies
Fig. 4: Rami's ratios (for p/t) as a function of the perpendicular and parallel velocities in the c.m. frame for the system 124Xe +124Sn at 32 A•MeV with a specific selection of QP.
12
Fig. 5: Bidimensional maps of experimental probabilities for a proton as a function of the perpendicular and parallel velocities in the c.m. frame for the system 124Xe +124Sn at 32 A⋅MeV with a specific selection of QP.
The mean velocity of the QP is indicated in Fig. 4 as well as the limit between the front and the back in the QP frame. For
comparison, we present, for the protons, in Fig. 5 different maps of probabilities in the velocity space for the same different
selections of events than for Fig. 4. We observe a remarkable qualitative agreement between the two methods of isolation of
the different contributions produced during a deep inelastic reaction around Fermi energy. For example, the blue parts of Fig. 4,
corresponding to the QP contribution (important memory of the initial isospin), are completely compatible with the map of
probability of being evaporated by the QP. We have the same trend for the other respective contributions. For the studied very
peripheral collisions, there is not isospin balance between the QP and the QC. Only the pre-equilibrium component around the
c.m velocity, is equilibrated of this point of view as well as the pre-equilibrium, that we observe on the Coulombian circles. It
seems also that there is a fast process of fragmentation, keeping an important memory of initial isospin of the nuclei in collision.
Indeed, we find a contribution coming from the target at the front of the emission sphere of the QP (in red in Fig. 4). We have
therefore seen that the use of nuclear systems with an important gradient of isospins between the two partners, can be a very
interesting tool to use with a 4π setup, to really understand the mechanism and the sequence of a nuclear reaction in the
velocity space. By using specifically the Rami's ratio in the velocity space, we have shown the great interest of this
representation to study the isospin transport during nuclear reaction and we have moreover confirmed experimentally the
validity of our method of probability determination.
13
New experimental approaches of the classical caloric curve to study the disintegration of hot nuclei
The richness of the set of data, collected by the INDRA collaboration during the last twenty years, enabled us to build a set
of caloric curves for nuclei of various sizes, by using, for the first time, a single experimental set-up and a single experimental
protocol. The experimental difficulties met usually to measure the temperature and the excitation energy of hot nuclei created
by nuclear reactions, have brought us to approach the calorimetry by a new method and to perform in a different way the usual
thermometry of such nuclei. We will therefore present the different caloric curves thus obtained in Fig. 6, for Quasi-Projectiles
produced by symmetric or quasi symmetric reactions at different incident energies (systems Xe+Sn, Ni+Ni, Ar+KCl ) [12]. For all
systems, at all incident energies, a change of behavior is observed, a clear break of slope corresponding to a change of the
mode of de-excitation of the hot nuclei.
A certain number of theoretical calculations showed that hot nuclei support an increase of temperature until a maximal
temperature, called limiting temperature Tlim, beyond which the nucleus may fragment [14-16]. This disintegration of the hot
nuclei is due to Coulomb instabilities. This phenomenon is observed in the framework of our study as we can seen it in Fig. 7
for the system Xe+Sn. Indeed, there is a total agreement between the apparition of a break of slope in the caloric curve and the
reach of this limiting temperature.
We thus observe clearly a transition from a nuclear Fermi gas to another state which might be a gas of particles and fragments.
Fig. 6: Experimental caloric curves obtained for different systems and incident energies..
Fig. 7: On the left, experimental caloric curves for the system Xe+Sn at different incident energies. On the right, evolution of measured temperatures as a function of QP mass for the same systems and energies
(the theoretical curves came from the references [15,16]).
QP
QP
14
Quantifying EOS symmetry energy withXe+Sn reactions
collaboration with M. ColonnaThis contribution is part of M. Kabtoul thesis and is related to an accepted article in the European Physics Journal [17].
The density (ρ) dependence of the symmetry term of the Nuclear Equation of State can be parameterized as
where ρ0 is the nuclear saturation density. The first term is related to Pauli correlations; the second term is the potential part.
The value of the γ exponent is linked to the asy-stiffness (γ ≥1) or asy-softness (γ <1) of the potential part. The value of γ is
presently unknown [18]. 32 A·MeV 124,136Xe+112,124Sn reactions were studied with the INDRA multidetector. Only products
detected in the forward centre of mass hemisphere are considered. Observables were measured as a function of an impact
parameter, considered as a dissipation scale. The scale is given by the total transverse energy of the light charged particles
(Z=1 and 2) detected in the forward c.m hemisphere (∑
12). Low (large) transverse energies correspond to peripheral
(central) collisions.
Isospin equilibration
Isospin, (N-Z)/A, transport tends to equilibrate the isospin content between the projectile and the target. This has been
studied as a function of the impact parameter using the isospin transport ratio [19] :
the index H refers to the n-rich system (136Xe+124Sn) and L to the n-poor system (124Xe+112Sn), M to the mixed reactions136Xe+112Sn and 124Xe+124Sn whose total N/Z are the same. The triton multiplicity has been used as isospin observable (x).
The evolution of Rt with impact parameter is displayed in Fig. 8. We recover the previous section result, i.e. for very
peripheral collision no isospin equilibration is observed where as isospin equilibration is reached above a transverse LCPenergy of about 100 MeV which corresponds to impact parameters below 6 fm.
Symmetry energy from isospin diffusion
The chosen isospin sensitive variable is the fragment (Z>2) multiplicity difference between the 136Xe+112Sn and124Xe+124Sn systems. It is presented as a function of the impact parameter scale in figure 8. Only products detected in the
forward c.m. hemisphere are considered and quasi-fusion events are removed [20]. The measured fragment multiplicity is
then the sum of fragments coming from quasi-projectile, QP, de-excitation and from mid-rapidity.
Fig. 8: Isospin transport ratio calculated for the measured multiplicity of tritons, for the four Xe+Sn systems at 32A MeV, as a function of dissipation.
15
For ∑
12>100 MeV isospin equilibrium is reached as demonstrated above. Thus the QP de-excitation properties are the
same for the two systems, in particular the multiplicity of emitted fragments. Therefore the fragment multiplicity difference
reduces to the difference between mid-rapidity multiplicities. Assuming that these multiplicities are not modified by the de-
excitation stage, the measured fragment multiplicity difference can be directly compared to transport model predictions for
primary fragments without any after burner hypothesis. This avoids resorting to a de-excitation code.
Stochastic Mean Field (SMF) [21] calculations were performed using two different parameterizations of the symmetry energy
(γ=1 and γ≈0.5). If we now compare data and simulated values (Figure 9), it appears that the asy-soft (γ≈0.5) case does not
follow the experimental trend, whereas the asy-stiff calculation well matches the data for b<6 fm (∑
12>100 MeV). For
more peripheral collisions, the comparison does not hold because isospin equilibrium is not reached, thus simulations and
data diverge.
Concerning the FAZIA project, the group was mainly involved in the capability and improvement of the so-called Pulse
Shape Analysis (PSA) for identification of stopped particles in one single silicon detector. During last period, two main
achievements were obtained.
Comparison of rear and front side injection for PSA identification
For the same FAZIA telescope (Si 300 µm-Si 500 µm-CsI) and electronic chain we recorded data, taken in the same
beam and target configuration, consisting of particles produced in heavy ion collisions at intermediate energy. The
experiment was performed in two steps. The first one with particles entering by the low electric field side (rear side injection)
in both silicons while in the second step they encountered first the high electric field (front side injection). This was simply
obtained by turning both silicon detectors by 180°. The silicon detectors fulfilled the last FAZIA specifications obtained during
a few years of R&D in terms of resistivity homogeneity over the whole surface (20 x 20 mm²), adequate crystal cutting along
the main axis to avoid channelling and bespoke electronic and digitization chains. In these conditions we were able to fairly
compare both configurations to determine the best solution in term of particle identification both in the usual ∆E-E (particles
punching through the first silicon Si1 and stopped in the second Si2) and PSA (for nuclei stopped either in Si1 or Si2)
methods.
∆E-E identification technique
It has been established that for the standard ∆E-E technique no significant variations of the identification capability
between both configurations have been observed. A very good charge separation for all incident particles as well as an
equal impressive isotopic discrimination up to Z=23 have been obtained with the same good quality criteria [22].
Fig. 9: Difference of the fragment multiplicities for the systems, 136Xe+112Sn and 124Xe+124Sn, versus the transverse energy of light charged particles. Close points show
the experimental data. Squares are related to SMF calculations using two parametrizations of the symmetry energy. (asysoft with γ=0.5 and asystiff with γ=1)
Pulse Shape Analysis for the FAZIA project
16
Pulse shape identification technique
For the front side injection configuration, the correlation between the energy and the maximum of the current signal (Imax)
does not give any visible identification. All elements merge together in a very compact cloud, corresponding to a strong
correlation between the energy and the maximum current. Thus the maximum amplitude of the current signal is not a good
PSA variable when the fragments enter through the high electric field side. Regarding the “Energy vs Charge rise-time"
correlations shown in Fig. 10, we obtain in both cases identification maps, although, the shape of the correlation is very
different in the two cases. For the front side injection, the charge rise-time continuously decreases with decreasing energy
for ions of any Z value. On the contrary, for rear side injection we observe, for a given Z and starting from high kinetic
energies, a rise-and-fall trend of the rise-time. For slow ions, this rise-and-fall produces a ridge where all Z values merge
together, whatever the particle is. In both cases a no-identification zone is visible for each line at low energy, defining a Z-dependent identification threshold. These thresholds will be determined more precisely in the following.
Particle identification thresholds for rear and front configuration
At first sight, the rear side injection method may seem more efficient, since it enlarges the ridge range. We need a
quantitative way to estimate the PSA identification thresholds. Therefore we apply the “Figure of Merit" (FoM) protocol for
adjacent peaks in the particle identification spectra. The FoM is defined as:
1 2
1 2 2.35
where µ1 and µ2 are the centroids, σ1 and σ2 the standard deviations of two Gaussians fitted to adjacent peaks. A value of
FoM=0.7 was conventionally chosen in order to extract a low energy threshold above which we realize a good identification.
In the case of two Gaussians, isolated, of equal intensity peaks, corresponds to a ratio peak/valley=2 and a correct
identification of 95% of the events (as an example, FoM=1 corresponds to 99%). The quantitative FoM method was applied
to both matrices of Fig. 10 in order to judge the identification quality for both configurations. The FoM=0.7 identification limit
criterion was again adopted.
Fig. 10: PSA technique: Energy vs rise-time of the charge signal for particles stopped in the first Silicon (Si1). Particles punching through the detector have been removed. From [22].
Fig. 11: Thresholds expressed in term of range in Silicon material for Z identification with ∆E(300µm)-E technique (black thick line) and with PSA technique (energy vs charge rise-time: red points are for rear side injection and blue points for front side injection.
17
The identification thresholds are summarized in Fig. 11 in terms of the range in Silicon, where a spectacular improvement
on the identification energy threshold for the rear side injection technique is observed (red line and full symbols). For the
front side injection case the range for identification varies from a minimum of 170 µm to about 250 µm, whereas in the rear
side injection case the minimum range presents a continuous increase, from 30 to 150 µm.
Under-depleted silicon detectors
Fig. 12: Energy versus Current maximum correlations at different bias voltages..
In a recent test, we have explored the identification capabilities of reverse mounted partially depleted detectors. In
such a configuration, the fragments enter the detector through an undepleted region, where the electric field is nominally
zero. In the following we will focus on PSA via the “Energy vs Current Maximum" method, since for partially depleted
detectors it shows the most promising results. In Fig. 12, “Energy vs Current Maximum" correlations are shown for different
bias voltages applied to a 500 µm thick Si2 stage. The full depletion voltage is 290 V. An improvement of isotopic
separation, above the identification energy thresholds, with decreasing bias voltage can be clearly spotted in the figure.
However the better mass resolution capability comes at the price of higher identification energy thresholds. Visual
inspection of Fig. 12 permits to evaluate the identification energy thresholds for different elements, reported as a function of
Z in Fig. 13. From Fig. 13, it is apparent that at 105 V and 130 V bias voltages the energy thresholds for charge
identification are slightly lower than those for mass identification. We would like to stress that the detector under test did not
allow isotopic identification via PSA when biased at full depletion voltage. In fact its doping uniformity is only about 6%,
while previous tests performed by the Collaboration showed that a doping uniformity of about 1% FWHM or less is needed
for isotopic identification at depletion bias voltage. On the other hand, when not fully depleted, PSA of detector signals
allowed for both charge and mass separation of fragments, though charge identification energy thresholds were higher than
at full depletion. Under-biasing the first stage of a ∆E-E telescope, one could still lower the energy thresholds for PSAisotopic identification, palliating thus an eventually poor doping uniformity.
Fig. 13: (Colour on line) Charge identification thresholds estimated from visual inspection of Energy versus Current maximum correlations (empty squares). Thresholds for the ∆E-
E techniques are also shown as filled triangles for 300 µm silicon thickness.
18
The high frequency digitization of the current signals induced by heavy ions in highly resistivity-homogeneous neutron
transmutation doped (n-TD) silicon detectors put in evidence the dependence of their shape on the type and energy of the
incident particle (Fig. 14) and related it to the characteristic local energy loss |dE/dx|.
This observation was recently interpreted in terms of charge carrier collection in a “dielectric” image. Our simple formalism –
developed in collaboration with IPN Orsay – supposes that electrons (e) and holes (h), created along the track of the ionizing
particle, are living for a while as exciton-like couples oriented by the electric field reigning in the detector. Multiplied by their
volume concentration, the electric moments of these dipoles lead to a supplementary dielectric bulk polarization described
by an enhanced relative permittivity ε’r>εr (εr=11.7 for silicon) implying a local distortion of the electric field [23]. In a
cylindrical geometry, ε’r is connected to the instantaneous linear density of carriers N(x,t), initially given by N0(x)=(1/w)|dE/dx|, (w=3.62 eV being the energy per e–h pair creation):
1 kN, , 1
The dissociation of the charge carrier couples is supposed to take place with a constant probability λ per time unit:
!,"
dN!,"dt
% 2
as long as the e-h pair linear density overpass a threshold, of low value Nth, the remainder being allowed to break down
without any delay. All the separated carriers drift towards the appropriate electrode by inducing, in accord with the Shockley-Ramo’s theorem, the current signal characteristic to each particle and eventually allowing its identification. A fit procedure,
based on the above equations and three fit parameters: λ, k and Nth, was used to get the best description of the individual
shape of the mean signal induced by several ions of known energy – see e.g. Fig. 15.
Description of current signals in Silicondetectors
collaboration with H. Hamrita
Fig 14: Mean current signals induced by ions of about 100 MeV impinging on the rear side of a n-TD silicon detector.
19
Fig. 16 (left) shows the dependence of the fit parameter k on the linear initial carrier density <N0> averaged over the particle
range“l” , while in Fig. 16 (right) one may see the relative variation of the related dielectric susceptibility χ= εr -1:
⟨'(
(⟩
(*⟨+0⟩ (3)
which connects the dielectric polarization vector to the electric field strength.
Fig. 15: Comparison between the simulated signals (dashed curves) and the mean experimental ones (solid curves) for two ions [24].
Fig. 16: Parameter k values (symbols) vs <N0>. The curves correspond to the fit with: the derivative of a Heaviside function (as suggested by the integral ʃ(k-k1)d<N0> in the inset) plus a constant term k1≈10-4 nm (solid curve) or the ratio of a monomial and a quadratic polynomial raised to a real power (dashed curve) (left).
The relative increase of the dielectric susceptibility at t=0 (symbols) averaged over the range of the ion vs <N0>. The curves correspond to the mentioned functions. The straight line simply assumes k=k1 (right).
Fig. 17: The dissociation time constant versus the ratio of <N0> and the averaged initial electric field, disturbed <Fin> (open symbols, dashed line) or not <F> (solid symbols, solid line).
The dielectric susceptibility is nearly doubling around
250 pairs/nm, speaking about a huge dielectric
polarization eventually locally induced for a few
nanoseconds [23]. The simulation shown in Fig. 15 is
very sensitive to the parameter λ and the associated
time constant τ = 1/λ is presented in a synthetic manner
in Fig. 17. By means of such a simple model and the
evidenced connection of its main parameters to the
stopping powers and the electric field, we count to
develop a global procedure of heavy ion identification in
silicon detectors.
20
References
[1] J.M. Lattimer and M. Prakash, The Physics of Neutron Stars, Science 304, 536 (2004)[2] C. Fuchs and H.H. Wolter, Eur. Phys. J. A 30, 5-21 (2006) and refs. therein[3] G. Lehaut et al. (INDRA collaboration), Phys. Rev. Lett. 104, 232701 (2010)[4] O. Lopez, INPC proceedings, EPJ web of conferences, (2013)[5] A. Rios and V. Somà, Phys. Rev. Lett. 108, 012501 (2012)[6] P.U. Renberg, D.F. Measday, M. Pepin, P. Schwaller, B. Favier, and C. Richard-Serre, Nucl.Phys. A 183, 81-104 (1972)[7] A. Nadasen et al., Phys. Rev. C 23, 1023-1044 (1981)[8] K. Kikuchi and M. Kawai, Nuclear matter and Nuclear Collisions, Ed. North Holland, New York (1968)[9] D. Coupland et al., Phys. Rev. C 84, 054603 (2011)[10] P. Danielewicz, Acta. Phys. Pol. B 33, 45 (2002)
[11] E. Vient, Mémoire HDR, Université de Caen -Basse Normandie(2006), http://tel.archives-ouvertes.fr/tel-00141924[12] E.Legouée, Ph.D Thesis, Université de Caen-Basse Normandie(2013), http://tel.archives-ouvertes.fr/tel-00881082[13] F. Rami, Phys. Rev. Letters 84, 6 (2000)[14] S. Levit, Nucl. Phys. A 437, 426-442 (1985)[15] Y. Zhang, Phys. Rev. C 54, 1137 (1996)[16] L. Zhang, Phys. Rev. C 59, 3292 (1999)[17] R. Bougault et al., Eur. Phys. J. A, Special topical issue on Symmetry energy (2014)[18] M.B. Tsang et al., Phys. Rev. C 86, 015803 (2012)[19] J. Rizzo et al. Nucl. Phys. A 806, 79 (2008)[20] M. Kabtoul, PHD Thesis, University of Caen (2013)[21] M. Colonna et al., Nucl. Phys. A 742, 337 (2004)[22] N. Le Neindre et al., Nucl. Instr. Meth. A 701, 145 (2013)[23] M. Parlog et al. (FAZIA collaboration), Nucl. Instr. and Meth. in Phys. Res. A 613 (2010) 290[24] H. Hamrita et al. (FAZIA collaboration), Nucl. Instr. and Meth. in Phys. Res. A 642 (2011) 59
References
[1] J.M. Lattimer and M. Prakash, The Physics of Neutron Stars, Science 304, 536 (2004)[2] C. Fuchs and H.H. Wolter, Eur. Phys. J. A 30, 5-21 (2006) and refs. therein[3] G. Lehaut et al. (INDRA collaboration), Phys. Rev. Lett. 104, 232701 (2010)[4] O. Lopez, INPC proceedings, EPJ web of conferences, (2013)[5] A. Rios and V. Somà, Phys. Rev. Lett. 108, 012501 (2012)[6] P.U. Renberg, D.F. Measday, M. Pepin, P. Schwaller, B. Favier, and C. Richard-Serre, Nucl.Phys. A 183, 81-104 (1972)[7] A. Nadasen et al., Phys. Rev. C 23, 1023-1044 (1981)[8] K. Kikuchi and M. Kawai, Nuclear matter and Nuclear Collisions, Ed. North Holland, New York (1968)[9] D. Coupland et al., Phys. Rev. C 84, 054603 (2011)[10] P. Danielewicz, Acta. Phys. Pol. B 33, 45 (2002)
[11] E. Vient, Mémoire HDR, Université de Caen -Basse Normandie(2006), http://tel.archives-ouvertes.fr/tel-00141924[12] E.Legouée, Ph.D Thesis, Université de Caen-Basse Normandie(2013), http://tel.archives-ouvertes.fr/tel-00881082[13] F. Rami, Phys. Rev. Letters 84, 6 (2000)[14] S. Levit, Nucl. Phys. A 437, 426-442 (1985)[15] Y. Zhang, Phys. Rev. C 54, 1137 (1996)[16] L. Zhang, Phys. Rev. C 59, 3292 (1999)[17] R. Bougault et al., Eur. Phys. J. A, Special topical issue on Symmetry energy (2014)[18] M.B. Tsang et al., Phys. Rev. C 86, 015803 (2012)[19] J. Rizzo et al. Nucl. Phys. A 806, 79 (2008)[20] M. Kabtoul, PHD Thesis, University of Caen (2013)[21] M. Colonna et al., Nucl. Phys. A 742, 337 (2004)[22] N. Le Neindre et al., Nucl. Instr. Meth. A 701, 145 (2013)[23] M. Parlog et al. (FAZIA collaboration), Nucl. Instr. and Meth. in Phys. Res. A 613 (2010) 290[24] H. Hamrita et al. (FAZIA collaboration), Nucl. Instr. and Meth. in Phys. Res. A 642 (2011) 59
Publications
Constrained caloric curves and phase transition for hot nucleiBorderie B., Piantelli S., Rivet M.F., Raduta A. R., Ademard G. et al.Physics Letters B 723, 1-3 (2013) 140-144
Nuclear multifragmentation time-scale and fluctuations of largestfragment sizeGruyer D., Frankland J.D., Botet R., Ploszajczak M., Bonnet E. et al.Physical Review Letters 110, 17 (2013) 172701
Comparison of charged particle identification using pulse shapediscrimination and ΔE−E methods between front and rear sideinjection in silicon detectorsLe Neindre N., Bougault R., Barlini S., Bonnet E., Borderie B. et al.NIM A 701 (2013) 145-152
Isospin transport in 84Kr + 112,124Sn collisions at Fermi energiesBarlini S., Piantelli S., Casini G., Maurenzig P.R., Olmi A. et al.Physical Review C 87 (2013) 054607
Effects of irradiation of energetic heavy ions on digital pulse shapeanalysis with silicon detectorsBarlini S., Carboni S., Bardelli L., Le Neindre N., Bini M. et al.NIM A 707 (2013) 89-98
X-ray fluorescence from the element with atomic number Z=120Frégeau M.O., Jacquet D., Morjean M., Bonnet E., Chbihi A. et al.Physical Review Letters 108 (2012) 122701
N and Z odd-even staggering in Kr + Sn collisions at Fermi energiesPiantelli S., Casini G., Maurenzig P.R., Olmi A., Barlini S. et al.Physical Review C 88 (2013) 064607
New isospin effects in central heavy-ion collisions at Fermi energiesGagnon-Moisan F., Galichet E., Rivet M.-F., Borderie B., Colonna M. et al.Physical Review C 86 (2012) 044617
A single-chip telescope for heavy-ion identificationPasquali G., Barlini S., Bardelli L., Carboni S., Le Neindre N. et al.European Physical Journal A 48 (2012) 158
Correlations between emission timescale of fragments and isospin dynamics in 124Sn+64Ni and 112Sn+58Ni reactions at 35A MeVDe Filippo E., Pagano A., Russotto P., Amorini F., Anzalone A. et al.Physical Review C 86 (2012) 014610
Particle identification using the (DELTA)E-E technique and pulse shape discrimination with the silicon detectors of the FAZIA projectCarboni S., Barlini S., Bardelli L., Le Neindre N., Bini M. et al.NIM A 664 (2012) 251-263
Publications
Constrained caloric curves and phase transition for hot nucleiBorderie B., Piantelli S., Rivet M.F., Raduta A. R., Ademard G. et al.Physics Letters B 723, 1-3 (2013) 140-144
Nuclear multifragmentation time-scale and fluctuations of largestfragment sizeGruyer D., Frankland J.D., Botet R., Ploszajczak M., Bonnet E. et al.Physical Review Letters 110, 17 (2013) 172701
Comparison of charged particle identification using pulse shapediscrimination and ΔE−E methods between front and rear sideinjection in silicon detectorsLe Neindre N., Bougault R., Barlini S., Bonnet E., Borderie B. et al.NIM A 701 (2013) 145-152
Isospin transport in 84Kr + 112,124Sn collisions at Fermi energiesBarlini S., Piantelli S., Casini G., Maurenzig P.R., Olmi A. et al.Physical Review C 87 (2013) 054607
Effects of irradiation of energetic heavy ions on digital pulse shapeanalysis with silicon detectorsBarlini S., Carboni S., Bardelli L., Le Neindre N., Bini M. et al.NIM A 707 (2013) 89-98
X-ray fluorescence from the element with atomic number Z=120Frégeau M.O., Jacquet D., Morjean M., Bonnet E., Chbihi A. et al.Physical Review Letters 108 (2012) 122701
N and Z odd-even staggering in Kr + Sn collisions at Fermi energiesPiantelli S., Casini G., Maurenzig P.R., Olmi A., Barlini S. et al.Physical Review C 88 (2013) 064607
New isospin effects in central heavy-ion collisions at Fermi energiesGagnon-Moisan F., Galichet E., Rivet M.-F., Borderie B., Colonna M. et al.Physical Review C 86 (2012) 044617
A single-chip telescope for heavy-ion identificationPasquali G., Barlini S., Bardelli L., Carboni S., Le Neindre N. et al.European Physical Journal A 48 (2012) 158
Correlations between emission timescale of fragments and isospin dynamics in 124Sn+64Ni and 112Sn+58Ni reactions at 35A MeVDe Filippo E., Pagano A., Russotto P., Amorini F., Anzalone A. et al.Physical Review C 86 (2012) 014610
Particle identification using the (DELTA)E-E technique and pulse shape discrimination with the silicon detectors of the FAZIA projectCarboni S., Barlini S., Bardelli L., Le Neindre N., Bini M. et al.NIM A 664 (2012) 251-263
21
Theoretical physics and phenomenology
F. Aymard*, D. Durand, F. Gulminelli, O. Juillet, A. Leprevost*
*PHD students
New Quantum Monte Carlo methods for the nuclear shell model
The nuclear shell model with configuration interaction is a powerful theoretical framework for studying the nuclear
structure [1]. Unfortunately, the exponential scaling of the many-body space with the number of valence nucleons or the size of
the single-particle basis strongly restricts its applicability. Quantum Monte-Carlo (QMC) methods are attractive techniques to
overcome such limitations by offering an alternative to the diagonalization of the Hamiltonian. Indeed, these approaches
reduces the many-body problem to a set of numerically tractable one-body problems describing independent particles that
randomly walk in fluctuating external fields. To date, the shell model Monte-Carlo method (SMMC) is the principal application of
QMC approaches to the shell model [2]. With schematic effective interactions, the SMMC method exactly reproduces the
properties of even-even and N=Z odd-odd nuclei at zero and finite temperature. However, with realistic effective interactions or
for other kinds of nuclei, the method is plagued by a dramatically vanishing signal-to-noise ratio that reveals the so-called
fermion sign/phase problem. Moreover, the SMMC approach cannot achieve a detailed spectroscopy of nuclei.
In such a context, we have proposed a new QMC approach for the shell model with the aim of reconstructing spectroscopy of
nuclei with a well-managed sign/phase problem [3]. The originality of this phaseless QMC formalism, firstly suggested by S.
Zhang and H. Krakauer in quantum chemistry [4], relies on an approximate wave function assuming two crucial roles. First, the
trial state initiates and guides the Brownian motion in order to improve the efficiency of the method according to the importance-
sampling technique. Second, it is also used to control the sign/phase problem through a constraint on stochastic realizations in
the spirit of fixed-node ab-initio calculations.
Reconstructing shell model eigenstates implies that the trial wavefunction must have the same quantum numbers. Furthermore,
the quality of the constrained-path approximation depends on the quality of the approximate state. A good trial wavefunction
can thus be obtained via a Hartree-Fock-like approach with variation after projection onto angular momentum (VAP). This
strategy for restoration of broken symmetries is rather usual in nuclear theory but remains at the cutting edge of variational
methods. Indeed, as a superposition of symmetry-related independent-particle states, the VAP solutions can absorb
correlations beyond the mean-field level. All the performed calculations prove that the VAP method yields good approximations
for all the considered observables and thus offers a relevant trial state.
Finally, the phaseless QMC scheme we proposed is based on a VAP wavefunction to initiate, guide, and constrain the
stochastic paths. The “yrast” energies obtained for sd- and pf-shell nuclei with realistic effective interactions agree remarkably
well with the values from exact diagonalization: For any spin, phaseless errors do not exceed 0.3% with statistical error bars
about 40-50 keV [3]. A convincing example is given by the spectrum of 27Na (these “yrast” energies are partially reproduced on
the right panel of Fig. 2). Indeed, the odd-mass nuclei are the most pathological cases in QMC simulations because they
induce a particularly serious sign/phase problem even with schematic interactions. In addition, the phaseless QMC approach
accurately reproduces the binding energies of 56Ni (see Fig. 1). The formalism also allows for a complete reconstruction of low-
lying spectroscopy through the determination of VAP wavefunctions orthogonal to the previously computed one. For instance, if|ψ/0 refers to the VAP ground state for any given angular momentum, the approximate first excited state of same spin is
obtained by minimizing the energy with the wavefunction Q2|ψ0, where |ψ0 is an independent-particle state projected onto the
desired quantum numbers and Q2 the projector onto the subspace orthogonal to |ψ/0.
22
By using the VAP solution |30 as the trial state in the
phaseless QMC approach, one then achieves a
stochastic sampling of the true first excited state. The
preliminary results obtained are promising, as shown in
Fig. 2 where samples of results from this extension of the
method are reported, for the first excited states of 28Mg
and 27Na respectively. Again, a very good agreement
between QMC and the exact results is obtained.
In conclusion, the phaseless QMC approach, with a
variational symmetry-restored wave-functions to guide
and constrain walkers, may be considered as a powerful
tool to address the structure of nuclei out of reach of
conventional shell model treatments that usually require
strong truncations of the configuration space.
Fig. 1: Binding energies of 56Ni as obtained with the VAP and phaseless QMC methods compared to the exact values extracted from [5]. The realistic GXPF1A effective interaction is considered [6]. The lighter areas indicate the QMC statistical errors.
Fig. 2: Observables for the two first 4 0, 2 and 4 5/2, 3/2 states of 28Mg and 27Na respectively, as obtained from VAP and QMC calculations and compared to exact values with the realistic USD [7] effective interaction.
23
Microscopic modelling of star matter
We are involved since several years in the theoretical modelling of the matter equation of state in the density and
temperature conditions where it can be described by nucleonic degrees of freedom [8], and in its applications for the
understanding of the neutron star structure and core-collapse supernova evolution. These works are in collaboration with IFIN
(Bucarest), IPNO (Orsay), IPNL (Lyon) and supported by the ANR SN2NS (2011-15).
At zero temperature, all the information is contained in the nuclear energy functional in its isoscalar and, more important,
isovector channels. Though generally agreed that the symmetry energy plays a dramatic role in determining the structure of
neutron stars and the evolution of core-collapsing supernovae, little is known in what concerns its value away from normal
nuclear matter density and, even more important, the correct definition of this quantity in the case of inhomogeneous matter.
Indeed, nuclear matter traditionally addressed by mean field models is uniform while clusters are known to exist in the dilute
baryonic matter which constitutes the main component of compact objects outer shells. We have investigated the meaning of
symmetry energy in the case of clusterized systems and the sensitivity of the proto-neutron star composition and equation of
state to the effective interaction. To this aim we have developed an improved Nuclear Statistical Equilibrium (NSE) model [9],
where the same effective interaction is consistently used to determine the clusters and unbound particles energy functionals in
the self-consistent mean-field approximation. In particular, it is well known that cluster self-energies should be deeply modified
in the nuclear medium. We have explored the ground-state properties of nuclear clusters embedded in a gas of nucleons with
the help of Skyrme-Hartree-Fock microscopic calculations [10]. We parameterize their density profiles in spherical symmetry in
terms of basic properties of the energy density functionals used and propose an analytical, Woods-Saxon density profile whose
parameters depend, not only on the composition of the cluster, but also of the nucleon gas. We have studied the clusters’
energies with the help of the local-density approximation, validated through our microscopic results. We found that the excluded
volume effect does not exhaust the in-medium effects and an extra isospin and density-dependent energy shift has to be
considered to consistently determine the composition of subsaturation stellar matter. The symmetry energy of diluted matter is
seen to depend on the isovector properties of the effective interaction, but its behavior with density and its quantitative value
are strongly modified by clusterization. Our studies provide a simple, but microscopically founded modeling of the properties of
clusterized matter at both zero and finite temperature, for direct use in consequential applications of astrophysical interest.
At super-saturation densities, the description of stellar matter is complicated by the emergence of the strangeness degree of
freedom. In collaboration with LUTH (Meudon), we have evaluated the phase diagram of a system constituted of neutrons and
L-hyperons in thermal equilibrium in the mean-field approximation [11]. We have shown that this simple system exhibits a
complex phase diagram with first and second order phase transitions. In a successive paper [12], we have analyzed the
complete three-dimensional space given by the baryon, lepton and strange charge. We show that the phase diagram at sub-
saturation densities is strongly affected by the electromagnetic interaction, while it is almost independent of the electric charge
at supra-saturation density. As a consequence, stellar matter under the condition of strangeness equilibrium is expected to
experience a first as well as a second-order strangeness-driven phase transition at high density, while the liquid-gas phase
transition is expected to be quenched (Fig. 3). An RPA calculation indicates that the presence of this critical point might have
sizable implications for the neutrino propagation in core-collapse supernovae.
Fig. 3: Borders of the phase-coexistence domains at zero temperature and strangeness chemical potential. Upper: (n, p, L)-mixture in the baryon versus charge density plane. Lower: (n, p,L, e)-mixture. Red: liquid-gas phase transition of non-strange dilute nuclear matter; blue: non-strange to strange phase transition.
The arrows mark the directions of phase separation.
24
Pairing and alpha-clustering at high excitation
The modification of nuclear structure at high excitation energy is poorly known. We particularly focus on pairing effects in
the nuclear level densities, and on the possible persistence of alpha-clustering in light even-even nuclei beyond the threshold for
multi-alpha emission. These studies are done by means of a series of dedicated experiments in collaboration with the
GARFIELD experimental collaboration.
Our first study has focused on the reactions 32S+58Ni and 32S+64Ni at 14.5 A·MeV [13]. Evidence was found for important odd-
even effects in isotopic observables of selected peripheral collisions corresponding to the decay of a projectile-like source. The
influence of secondary decays on the staggering was studied with a correlation function technique. It was shown that this method
is a powerful tool to get experimental information on the evaporation chain, in order to constrain model calculations. Specifically,
we show that odd-even effects are due to interplay between pairing effects in the nuclear masses and in the level densities.
In a successive experiment [14], dissipative 12C+12C reactions at 95 MeV were fully detected in charge with the GARFIELD and
RCo apparatuses at LNL. A comparison to a dedicated Hauser-Feshbach calculation allows to select events which correspond,
to a large extent, to the statistical evaporation of highly excited 24Mg, as well as to extract information on the isotopic distribution
of the evaporation residues in coincidence with their complete evaporation chain. Residual deviations from a statistical behavior
were observed in alpha yields and attributed to the persistence of cluster correlations well above the 24Mg threshold for 6 alpha’s
decay (Fig. 4).
Fig. 4: Experimental (black dots) and calculated (red lines) relative energy distributions of the two alpha’s in coincidence with an oxygen in dissipative (left) and non-dissipative (right) events. In the left panel, a zoom on the low relative energy region with a reduced energy binning is
shown in the figure inset, to better see the structures of the energy correlation.
Generic phenomena in nuclear physics at finite temperature
The development of finite temperature mean-field and cluster models for nuclear physics and astrophysics applications
has allowed us to evidence generic phenomena in statistical mechanics, which can potentially lead to interdisciplinary
applications.
A first application concerns ensemble inequivalence in finite systems [15] as well as at the thermodynamic limit [16]. We
explore the conditions under which the particle number conservation constraint deforms the predictions of fragmentation
observables as calculated in the grand-canonical ensemble. We derive an analytical formula allowing extracting canonical
results from a grand-canonical calculation and vice-versa. This formula shows that exact canonical results can be recovered for
observables varying linearly or quadratically with the number of particles, independent of the grand-canonical particle number
fluctuations. We explore the validity of such grandcanonical extrapolation for different fragmentation observables in the
framework of the analytical Grand Canonical or Canonical Thermodynamical Model [(G)CTM] of nuclear multifragmentation
(Fig. 5). It is found that corrections to the grandcanonical expectations can be evaluated with high precision, provided the
system does not experience a first-order phase transition.
25
In particular, because of the Coulomb quenching of the liquid-gas phase transition of nuclear matter, we find that mass
conservation corrections to the grandcanonical ensemble can be safely computed for typical observables of interest in
experimental measurements of nuclear fragmentation, even if deviations exist for highly exclusive observables.
A second application [17] consists in the exploration of the connections between the description of interacting particles
systems in terms of energy density functionals, as it is done for self-consistent mean-field nuclear physics models, and
fractional exclusion statistics (FES) introduced in different condensed matter applications. We have considered a generic
interacting particle system in the quasi-classical limit and in the mean-field approximation. We have defined the FES
quasiparticle energies, we calculate the FES parameters of the system and we deduce the equations for the equilibrium
particle populations. The FES gas is “ideal", in the sense that the quasiparticle energies do not depend on the other
quasiparticle levels populations and the sum of the quasiparticle energies is equal to the total energy of the system. We have
proved that this FES formalism is equivalent to the semi-classical or Thomas Fermi (TF) limit of the self-consistent mean-field
theory and the FES quasiparticle populations may be calculated from the TF populations by making the correspondence
between the FES and the TF quasiparticle energies.
Fig. 5: In the upper-left panel and lower left panel canonical (solid lines) and grand canonical (dotted lines) mass distribution and largest cluster probability distribution are shown for A=50 (black) and 400 (red) at T=4 MeV. In the upper-right panel and lower right panel the same observables are plotted for a system A=200 at
T=3 MeV (black) and 7 MeV (red) ).
26
Publications
α-clustering effects in dissipative 12C+12C reactions at 95 MeVBaiocco G., Morelli L., Gulminelli F., D'Agostino M., Bruno M. et al.Physical Review C 87 (2013) 054614
Transformation between statistical ensembles in the modelling of nuclear fragmentationChaudhuri G., Gulminelli F., Mallik S.Physics Letters B 724 (2013) 115-120
Densities and energies of nuclei in dilute matter at zerotemperaturePapakonstantinou P., Margueron J., Gulminelli F., Raduta A.Physical Review C 88 (2013) 045805
Strangeness-driven phase transition in star matterGulminelli F., Raduta A., Oertel M., Margueron J.Physical Review C 87 (2013) 055809
Equivalence between fractional exclusion statistics and Fermi liquid theory in interacting particle systemsAnghel D.V., Nemnes G.A., Gulminelli F.Physical Review E 88 (2013) 042150
A Constrained-Path Quantum Monte-Carlo Approach for the Nuclear Shell ModelBonnard J., Juillet O.Physical Review Letters 111 (2013) 012502
Exotic spin, charge and pairing correlations of the two-dimensional doped Hubbard model: a symmetry entangled mean-field approachJuillet O., Frésard R.Physical Review B (Condensed Matter) 87 (2013) 115136
Towards an understanding of staggering effects in dissipative binary collisionsD'Agostino M., Bruno M., Gulminelli F., Morelli L., Baiocco G. et al.Nuclear Physics A 875 (2012) 139-159
Phase transition towards strange matterGulminelli F., Raduta A., Oertel M.Physical Review C 86 (2012) 025805
Ensemble inequivalence in supernova matter within a simple modelGulminelli F., Raduta A.Physical Review C 85 (2012) 025803
Publications
α-clustering effects in dissipative 12C+12C reactions at 95 MeVBaiocco G., Morelli L., Gulminelli F., D'Agostino M., Bruno M. et al.Physical Review C 87 (2013) 054614
Transformation between statistical ensembles in the modelling of nuclear fragmentationChaudhuri G., Gulminelli F., Mallik S.Physics Letters B 724 (2013) 115-120
Densities and energies of nuclei in dilute matter at zerotemperaturePapakonstantinou P., Margueron J., Gulminelli F., Raduta A.Physical Review C 88 (2013) 045805
Strangeness-driven phase transition in star matterGulminelli F., Raduta A., Oertel M., Margueron J.Physical Review C 87 (2013) 055809
Equivalence between fractional exclusion statistics and Fermi liquid theory in interacting particle systemsAnghel D.V., Nemnes G.A., Gulminelli F.Physical Review E 88 (2013) 042150
A Constrained-Path Quantum Monte-Carlo Approach for the Nuclear Shell ModelBonnard J., Juillet O.Physical Review Letters 111 (2013) 012502
Exotic spin, charge and pairing correlations of the two-dimensional doped Hubbard model: a symmetry entangled mean-field approachJuillet O., Frésard R.Physical Review B (Condensed Matter) 87 (2013) 115136
Towards an understanding of staggering effects in dissipative binary collisionsD'Agostino M., Bruno M., Gulminelli F., Morelli L., Baiocco G. et al.Nuclear Physics A 875 (2012) 139-159
Phase transition towards strange matterGulminelli F., Raduta A., Oertel M.Physical Review C 86 (2012) 025805
Ensemble inequivalence in supernova matter within a simple modelGulminelli F., Raduta A.Physical Review C 85 (2012) 025803
References
[1] E. Caurier, G. Martínez-Pinedo, F. Nowacki, A. Poves, & A. P. Zuker, Rev. Mod. Phys. 77, 427 (2005).[2] S. E. Koonin, D. J. Dean, & K. Langanke, Phys. Rep. 278, 1 (1999), and references therein.[3] J. Bonnard & O. Juillet, Phys. Rev. Lett. 111, 012502 (2013).[4] S. Zhang & H. Krakauer, Phys. Rev. Lett. 90, 136401 (2003).[5] S. Pittel & B. Thakur, Acta Phys. Pol. B 42, 427 (2011).[6] M. Honma, T. Otsuka, B. A. Brown, & T. Mizusaki, Eur. Phys. J. A 25, 499 (2005).[7] B. H. Wildenthal, Prog. Part. Nucl. Phys. 11, 5 (1984).[8] F.Gulminelli, “Neutron rich nuclei and the equation of state of stellar matter”, Phys. Scripta T152, 014009 (2013)[9] Ad. R. Raduta, F. Aymard, F. Gulminelli, "Clusterized nuclearmatter in the (proto-)neutron star crust and the symmetryenergy", EPJA 50 (2014) 24[10] P. Papakonstantinou, J. Margueron, F. Gulminelli, Ad.R. Raduta, "Densities and energies of nuclei in dilute matter", Phys. Rev. C 88, 045805 (2013) [11] F. Gulminelli, Ad. Raduta,M. Oertel, "Phase transition
toward strange matter", Phys. Rev. C 86, 025805 (2012)[12] F. Gulminelli, Ad. Raduta,M. Oertel, “Coulomb effects in strangeness-driven phase transition of stellar matter », Phys. Rev. C 87, 055809 (2013) [13] M. D'Agostino, M. Bruno, F. Gulminelli, L. Morelli, G. Baiocco, & the GARFIELD collaboration , “Towards an understanding of staggering effects in S+Ni collisions”, Nucl. Phys. A 875, 139 (2012). [14] G. Baiocco, L. Morelli, F. Gulminelli & the GARFIELD collaboration, “alpha-clustering effects in dissipative C+C reactions at 95 MeV”, Phys. Rev. C 87, 054614 (2013) [15] G. Chaudhuri, F. Gulminelli & S.Mallik, “On the effect of particle number conservation in nuclear fragmentation”, Phys. Lett. B 724 , 115 (2013).[16] F. Gulminelli & Ad. R. Raduta, « Ensemble inequivalence in supernova matter within a simple model », Phys. Rev. C 85, 025803 (2012).[17] D.V. Anghel, G.A. Nemnes & F. Gulminelli, "Equivalence between fractional exclusion statistics and self-consistent mean-field theory in interacting particle systems in any number of dimensions", Phys. Rev. E 88 , 042150 (2013).
References
[1] E. Caurier, G. Martínez-Pinedo, F. Nowacki, A. Poves, & A. P. Zuker, Rev. Mod. Phys. 77, 427 (2005).[2] S. E. Koonin, D. J. Dean, & K. Langanke, Phys. Rep. 278, 1 (1999), and references therein.[3] J. Bonnard & O. Juillet, Phys. Rev. Lett. 111, 012502 (2013).[4] S. Zhang & H. Krakauer, Phys. Rev. Lett. 90, 136401 (2003).[5] S. Pittel & B. Thakur, Acta Phys. Pol. B 42, 427 (2011).[6] M. Honma, T. Otsuka, B. A. Brown, & T. Mizusaki, Eur. Phys. J. A 25, 499 (2005).[7] B. H. Wildenthal, Prog. Part. Nucl. Phys. 11, 5 (1984).[8] F.Gulminelli, “Neutron rich nuclei and the equation of state of stellar matter”, Phys. Scripta T152, 014009 (2013)[9] Ad. R. Raduta, F. Aymard, F. Gulminelli, "Clusterized nuclearmatter in the (proto-)neutron star crust and the symmetryenergy", EPJA 50 (2014) 24[10] P. Papakonstantinou, J. Margueron, F. Gulminelli, Ad.R. Raduta, "Densities and energies of nuclei in dilute matter", Phys. Rev. C 88, 045805 (2013) [11] F. Gulminelli, Ad. Raduta,M. Oertel, "Phase transition
toward strange matter", Phys. Rev. C 86, 025805 (2012)[12] F. Gulminelli, Ad. Raduta,M. Oertel, “Coulomb effects in strangeness-driven phase transition of stellar matter », Phys. Rev. C 87, 055809 (2013) [13] M. D'Agostino, M. Bruno, F. Gulminelli, L. Morelli, G. Baiocco, & the GARFIELD collaboration , “Towards an understanding of staggering effects in S+Ni collisions”, Nucl. Phys. A 875, 139 (2012). [14] G. Baiocco, L. Morelli, F. Gulminelli & the GARFIELD collaboration, “alpha-clustering effects in dissipative C+C reactions at 95 MeV”, Phys. Rev. C 87, 054614 (2013) [15] G. Chaudhuri, F. Gulminelli & S.Mallik, “On the effect of particle number conservation in nuclear fragmentation”, Phys. Lett. B 724 , 115 (2013).[16] F. Gulminelli & Ad. R. Raduta, « Ensemble inequivalence in supernova matter within a simple model », Phys. Rev. C 85, 025803 (2012).[17] D.V. Anghel, G.A. Nemnes & F. Gulminelli, "Equivalence between fractional exclusion statistics and self-consistent mean-field theory in interacting particle systems in any number of dimensions", Phys. Rev. E 88 , 042150 (2013).
27
Nuclear waste management
Medical and industrial applications
RESEARCH
INTERDISCIPLINARY RESEARCH
28
Nuclear waste management
Over the past two years, in the framework of the GUINEVERE experiment and FREYA program we have pursued the experiments
carried out at the subcritical, lead moderated VENUS-F fast core. Pulsed Neutron Source measurements (PNS) and short continuous beaminterruptions were performed and analysed in order to estimate the reactivity of various configurations of the reactor.The second part of our activities was devoted to the development of an original experimental device in the framework of the FALSTAFF projectwhose objective is the study of fission using the neutron source facility (NFS) at SPIRAL2.
G. Ban, T. Chevret*, F-R. Lecolley, J-L. Lecouey, G. Lehaut, N. Marie-Nourry
Collaboration : LPSC Grenoble, IPHC Strasbourg, SCK.GEN Mol (Belgique), CEA Cadarache, CEA/IRFU Saclay, GANIL Caen
*PHD student
The GUINEVERE Experiment
Brief description
The GUINEVERE (Generator of Uninterrupted Intense NEutrons at the lead Venus REactor) experiment [GUI] is dedicated
to feasibility studies for Accelerator Driven Systems (ADS) which are envisaged in partitioning and transmutation strategies. It
aims at providing a zero power experimental facility to investigate sub-criticality on-line monitoring procedures and to validate
simulation tools. These issues are of major importance in view of the achievement of a future powerful ADS such as the
MYRRHA project [MYR]. The GUINEVERE facility is hosted at the SCK CEN site in Mol (Belgium) and consists in the coupling
of the fast VENUS-F reactor to a neutron source provided by the GENEPI-3C accelerator.
The fast VENUS-F reactor consists of square fuel assemblies (FA) composed of a 5 × 5 pattern mixture of fuel and solid lead
rodlets, the latter acting as a fast system coolant. Radially and axially the fissile zone is surrounded by lead reflectors. The
outer side length of a FA is 80 mm. The fuel is 30% 235U enriched metallic uranium provided by CEA. The FA are arranged in a
cylindrical geometry (~800 mm in diameter, 600 mm in height). The VENUS-F core is equipped with six safety rods, two control
rods (CR) and an absorbent rod (PEAR rod).
The GENEPI-3C accelerator [GUI] provides neutrons via T(d,n)4He fusion reactions. It accelerates deuteron ions up to the
energy of 220 keV and guides them onto a tritiated target located at the VENUS-F core centre. This provides a quasi-isotropic
field of about 14 MeV neutrons. It can be operated in continuous mode or in pulsed mode with adjustable frequency.
29
In a first step, a critical configuration called CR0 was loaded and experimentally characterized [CR0]. In a second step, a sub-
critical configuration called SC1 (keff~0.96) was obtained by replacing the four central FA by the device devoted to the
accelerator pipe hosting.
Estimate of the reactivity of SC1 configuration using the MSM method
The MSM method has been used to estimate the reactivity of the so-called SC1 configuration of the VENUS-F core for
different heights of the two control rods (see table 1). This reference measurement of SC1 subcritical level configurations by
MSM method was used to estimate the reliability of the other methods of reactivity determination which could be applied in
industrial ADS facilities. These methods (PNS, Source Jerk, Beam Interruption and others) have been investigated in the
GENEPI-3C-driven subcritical VENUS-F core in the framework of the FREYA Project [FREYA] during the past two years.
Pulsed Neutron Source measurements – Area method
The “current-to-flux” technique was proposed to be combined to absolute reactivity measurements in order to establish a
complete on-line reactivity measurement procedure for ADS [MUSE]. The absolute reactivity values are foreseen to be
deduced from dynamical measurements requiring source variations. The study of the techniques used to analyse such
measurements is one of the purposes of the GUINEVERE program. To evaluate their accuracy, they have to be applied in
Pulsed Neutron Source (PNS) conditions for a given reactivity and their results have to be compared to the reference value
given by the MSM method.
One of the first methods investigated was the Area method [AREA] also referred as the Sjostrand method. It is based on the
analysis of the time dependent response of detectors placed in the reactor to a pulsed neutron excitation and it allows
determining in a straightforward way the reactivity of a subcritical nuclear reactor with no input from theoretical calculations as
long as the assumptions of the neutron point kinetics holds in the reactor. Indeed within the one-delayed group approximation
the equation of the time decrease of the neutron population (Eq. 1) after a pulse exhibits two components: a fast one due to
prompt neutrons and a slow one due to delayed neutrons leading by simple integration over time respectively to the prompt
surface Ap and the delayed surface Ad.
Then, the ratio of these two surfaces gives directly the value of the antireactivity in dollars (Eq 1).
(1)
Configuration CR height (mm)
MSMρρρρ$
AREAρρρρ$
BIMρρρρ$
SC1/CR@600 mm 600 -5.08±0.13 -5.09±0.03 -5.06±0.02
SC1 479.3 -5.28±0.13 -5.26±0.03 -5.29±0.02
SC1/CR@200 mm 200 --- -5.90±0.15 -5.89±0.02
SC1/CR@0 mm 0 -6.33±0.13 -6.31±0.05 -6.30±0.03
Table 1: Average reactivity value given by the Area method (AREA) and the Beam Interruption method (BIM) compared with the MSM reference value, for the different reactor configurations.
− ρ$=
Ap
Ad
= −ρ
βeff
Experimentally, for a set of pulses repeated with a
fixed frequency, a single PNS histogram (an
example is shown in Fig. 1) is constructed by
summing all the detector time responses as a
function of the time elapsed after the neutron
pulse. After integrating the time spectrum to get
the surfaces Ap and Ad, the antireactivity can be
calculated using Eq. 1.
Fig. 1: Time-dependent PNS histograms obtained with four different fission chambers.
30
If the dispersion of the reactivity values given by the Area method is due to spatial effects, it should be possible to use Monte
Carlo simulations of neutron pulses to correct for these effects since Monte Carlo simulations transport neutrons without
approximations. MCNP [MCNP] correction factors were then calculated for each configuration and each detector location with
a simplified version of the VENUS-F reactor. Corrected values are symbolized by open squares on Fig. 2. Except for the fission
chambers installed in the outer lead reflector, the corrected values are all compatible with the value given by the MSM method.
Finally, discarding the results obtained for the fission chambers located in the outer part of the reflector, the average corrected
value of reactivity was calculated for the three configurations studied. To calculate the uncertainty, it was assumed
conservatively that the correlations are at maximum between the values given by the detectors. As can be seen in Table 1, the
agreement between the MSM reactivity and the Area Method is remarkable.
Continuous Beam measurement - Beam Interruption Method
Thanks to the presence of an external source in an ADS, one can extract the reactivity of the sub-critical reactor using
interruptions of the source in a continuous mode within the neutron point kinetic model (Equation 4).
(2)
With ρ$ (t) the reactivity in dollar, n(t) the neutron population, n(t) the constant neutron population level before the beam
interruption, Λeff the mean generation time, β eff the effective delayed-neutron fraction, β ieff the effective delayed-neutron
fraction of the delayed-neutron group i, λi the decay constant of the delayed-neutron group i, and G the number of delayed-
neutron groups.
If one assumes that point kinetic holds in the reactor, all the detector count rates evolve the same way as the neutron
population and n(t) can be replaced in Eq. 2 by count rates from any detector and the reactivity is then readily extracted, once
the kinetic parameters have been calculated using the deterministic code ERANOS [ERA].
During the experiment, beam interruptions were performed with a period of 25 ms (40 Hz) and the source was switched off for
2 ms. Fission event coming from fission chambers (FCs) were time stamped over a time range including each beam trip plus
and minus 300 ms. For each FC, the histogram is obtained by summing all the time responses as a function of the time
elapsed after each source jerk. Figure 3 shows histograms normalized to the same maximum for different detector location: in
the core (CFUF34), in the inner part of the reflector (RS-10071) and in the outer part of the reflector (RS-10075).
Fig. 2: Uncorrected (solid dots) and corrected (open squares) reactivity values extracted from detector counts for the reactor configuration SC1. The MSM reference value is the dashed line and its uncertainty range is given by the
solid lines.
The area method was applied to reaction rates measured by
ten fission chambers during the PNS experiments for the
three different subcritical configurations obtained by moving
the control rods. The beam frequency was tuned at 220 Hz.
Fig. 2 shows the results for the SC1 configuration. Similar
results were obtained for the other configurations derived
from SC1. Reactivity values extracted according to Eq. 1 are
represented by solid dots. The error bars were calculated by
taking into account the statistical as well as the systematic
errors. The horizontal dashed line represents the reactivity
of the subcritical configuration as measured using the MSM
method, while the solid horizontal lines show the uncertainty
range on the MSM value.
One notices a dispersion of the results, which seem to
depend on the detector location in the reactor. Three groups
can be identified. The first one contains only the CFUF34
detector, which is the only one located in the reactor core. It
is also the only one from which the reactivity value obtained
with the Area method is in very good agreement with that of
the MSM method.
The second group gathers six detectors, which are located
either at the core-reflector interface or in the corners of the
grid, in the inner part of the reflector. The last detectors
(RS10075, CFUL653 and CFUL659) form the third group
and are located rather far away from the core, in the outer
part of the reflector. Clearly the Area Method fails at
providing the correct value of the reactivity when the
detectors are not in the core. The effect seems to be
stronger when the detector is farther from the core.
( )( )
( )
∑ ∫∑
−−−G
=i
t
=t'
iλiλ
eff
ieffG
=i
iλ
eff
ieff
0
eff
eff
$ dt't'
et'nt
eβ
β+
te
β
βn+
dt
dn
β
Λ
tn+=tρ
1 01
11
31
Fig. 3: MCNP simulations (red with concrete walls, black without) compared to experimental data (blue) for three detectors at three different locations: CFUF34 in the core (left), RS-10071 in the inner reflector (centre) and RS-10075 in
the outer reflector (right).
At first, the neutron population decreases right after
the source jerk, which corresponds to the prompt
neutron population decrease. Then, more or less
rapidly depending on the position of the detector, the
neutron population tends to reach its delayed neutron
level. As can be observed, the shape of the neutron
population histogram over time strongly depends on
the position of the detector in the reactor, as in the
case of the PNS experiments. The CFUF34 detector
seems to be the only one in agreement with Point
Kinetics. Moreover, the farther the detector from the
centre of the reactor, the more different the
experimental shapes are from that predicted by Point
Kinetics, and the later the neutron population reaches
its delayed neutron level. This clearly indicates the
presence of spatial effects that are not considered in
Point Kinetics.
In Fig. 4, the reactivity values (denoted “raw
reactivity”) given by the analysis of ten time dependent
FC count rate histograms using equation 2 and taking
into account several corrections (dead time, duty
cycle, etc…) are shown as solid black circles and
compared to the reference values given by the MSM
method.
Fig. 4: Raw reactivity values (solid dots) and corrected reactivity values (open squares) for each detector and for the four configurations studied: SC1/CR@0 mm at the upper left corner of the figure, SC1/CR@240 mm at the upper right corner, SC1 at the bottom left corner and
SC1/CR@600 mm at the bottom right corner. The MSM reference value is symbolized by the dashed line (red), and the solid lines (red) are its uncertainty range.
32
As expected, the reactivity extracted depends strongly on the detector position. The CFUF34 detector, which is located
inside the core and which exhibits a neutron population shape closer to that given by Point Kinetics, is the only one giving
an anti-reactivity in agreement with the MSM reference values. The anti-reactivity values obtained using the six detectors
located in the inner reflector are significantly underestimated and gathered around the same value. As for the detectors
located in the outer reflector, they give reactivity values even farther off. This is not surprising since they exhibit the time
responses which are the least similar to those given by Point Kinetics.
In order to investigate the origin of these strong spatial effects that are not considered in Point Kinetics and lead to such
scatter of the results, Monte Carlo simulations were carried out using MCNP and a simplified reactor geometry. At first,
simulations were done without the concrete walls surrounding the reactor vessel and fail to reproduce the diversity of the
experimental FC time histograms, all the simulated count rate evolution shapes being similar. However, when simulations
include the concrete walls around the reactor, experimental shapes are well reproduced (see Fig. 3). Neutrons leaving the
reactor can collide with the concrete wall elements, and thus may have their energy greatly reduced by collisions on light
elements in the walls. Since the FC deposits are made of 235U whose cross-section is the largest for low-energy neutrons,
the influence of a small amount of slowed-down neutrons on the detector count rates can become quite significant. It
appears that the concrete walls must be considered as a part of the reactor reflector.
The fact that taking into account the concrete walls in the geometry allows reproducing the experimental data with a very
good agreement opens up a way to correct the raw reactivity values obtained experimentally. The corrected results are
shown as open squares in Fig. 4. An impressive consistency between the MSM reference values and the corrected ones
derived from beam interruption analyses is observed. As expected given the comparison between experimental data and
Point Kinetics, the reactivity obtained from the CFUF34 detector located in the core is almost left unchanged by the
correction. Except for CFUL01-658, we observe that all detectors provide final reactivity values in agreement with the MSM
method for all the configurations studied. It is important to note that, in industrial ADS, it might be difficult to install detectors
in the reactor core due to the high flux that would prevail in it. Being able to correct the spatial effects that occur in the inner
and the outer reflector is therefore an important result.
To conclude with the extraction of the reactivity by studying the evolution of the neutron population during a beam
interruption, Table 1 gathers the reactivity value obtained for each configuration by averaging the results from all detectors,
and the MSM reference values. The uncertainties were computed assuming maximum correlations between the values
given by the detectors. The agreement between the MSM technique and the beam interruption analysis method is very
good.
Conclusion
Taking advantage of the different operating mode of the GENEPI3-C accelerator, two different methods to estimate the
reactivity of a sub-critical reactor based on the analysis of the evolution of the neutron population have been tested on data
collected at the GUINEVERE facility within the FREYA project: the Area method with a Pulsed Neutron Source and the
Beam Interruption method with a Continuous Beam. The data analysis, using point kinetics theory, has been applied to
count rates obtained with ten fission chambers located in the VENUS-F reactor. First, various shapes for the time
dependent FC count rates were observed depending on the FC position. That indicated the presence of spatial effects, that
appear to get stronger as the location of the detector is farther away from the core centre. MCNP simulations have then
been used to compute correction factors in order to correct the raw reactivities obtained from the point kinetics analysis.
Finally, corrected reactivity values are compatible with the MSM reference ones.
Brief description of the project
The FALSTAFF project [FALS] aims at providing highly constraining data to significantly improve the description of the
fission process. More specifically, the goal is to measure the neutron multiplicity as a function of the fragment
characteristics (mass, nuclear charge and kinetic energy) in neutron-induced fission of specific actinides in the MeV range.
New developments on microscopic calculations and the future generation of nuclear reactors are two of the main
motivations for new experimental programs devoted to the study of fission.
The FALSTAFF Project
33
Ionization chamber with scintillating gas
In order to minimize energy straggling of fission fragments, one possibility is to use ionization chamber (IC) not only to
identify and measure the energy of the fission fragments but also to measure their velocity via the well-known time-of-flight
technique. However the time response of an IC does not reach the resolutions required for a good determination of the fission
fragment velocity. That is the reason why we have developed an IC filled with scintillating gas and coupled to a pair of
photomultipliers (PMT) through transparent windows (Fig. 5). The light emitted by the gas provides the stop signal for the time-
of-flight measurement.
During the past two years, this scintillating IC has been qualify using several gas (N2, CF4) at different pressure, ranging from
atmospheric pressure down to 200 mbar, with alpha particle and fission fragment emitted by a 252Cf source.
The energy resolution (table 2) has been determined using a tri-alpha source at atmospheric pressure.
Fig. 5: Sketch of the ionization chamber with scintillating gas
Ealpha (MeV) σσσσ (keV) – N2 σσσσ (keV) – CF45.14 143 87
5.44 115 85
5.80 106 80
Table 2: σ (keV) of each alpha peaks for the different gas
Fig. 6: Left: correlation plot of the PMT, right: time distribution of correlated events in both PMT. Top: CF4, bottom: N2.
Fig. 6, left part, shows the correlation distribution
between the number of photo-electron detected in each
PMT for CF4 and N2 gas respectively, at atmospheric
pressure and with an alpha source. The coincidence
time resolutions extracted from the gaussian fits (Fig. 6,
right part) are σ=0.34 ns in CF4 and 1.4 ns in N2.
Fig. 7 shows the correlation distribution between the
number of photo-electron detected in each PMT for the
CF4 gas at different pressure and with a californium 252
source. By selecting events upper the red line, we have
then measured the coincidence time resolution
associated to fission fragment. At the lowest pressure
(250 mbar) a coincidence time resolution of σ=210 ps
was found, leading to a time resolution of σ=150 ps for
each PMT.
34
Conclusion
Despite a good time resolution when using the CF4 gas, the performance of our scintillating ionization chamber does
not meet the FALSTAFF requirement if one wants to measure fission fragment masses after neutron evaporation with an
accuracy of 1 mass unit. However, this kind of detector can be envisaged in other applications, e.g. cross-section
measurement of alpha particle production in neutron induced reaction on oxygen below 20 MeV with the use of a gas
mixture (CF4 + CO2). This latter reaction is of interest for the community and is one of the request of the High Priority
Request List of the NEA/OCDE [HPRL]
References
[AREA] – N.G. Sjostrand, Arkiv för Fysik Band 11 nr 13, 233 (1956)[CR0] – W. Uyttenhove et al., “Experimental Results from the VENUS-F Critical Reference State for the GUINEVERE Accelerator Driven System Project”, Proceeding of the Int. Conf. on Advancements in Nuclear Instrumentation, Measurement Methods and their Application, ANIMMA, Ghent, Belgium (June 6-9 2011).[ERA] – M. Carta, private communication[FALS] – F.R. Lecolley et al., AccApp 2013, Bruges (Belgium)[FREYA] – FREYA collaboration, FP7-269665
[GUI] – A. Billebaud et al., “The GUINEVERE Project for Accelerator Driven System Physics”, Proceedings of Global 2009, Paris, France (September 6-11, 2009).[HPRL] – http://www.oecd-nea.org/dbdata/hprl/[MCNP] – MCNP - A General Monte Carlo N-Particle Code, Version 5, LA-ORNL, RSICC LA-UR-03-1987, Los Alamos National Laboratory (2003)[MUSE] – MUSE collaboration, 5th EURATOM FP-Contract#FIKW-CT-2000-00063. Deliverable #8: Final Report (2005)[MYR] – H.A. Abderrahim et al., “MYRRHA Technical Description”, Technical Report for the OECD MYRRHA Review Team, SCK CEN, Belgium (2008).
Publication
Experimental Results From the VENUS-F Critical Reference State for the GUINEVERE Accelerator Driven System ProjectUyttenhove W., Baeten P., Ban G., Billebaud A., Chabod S. et al.IEEE Transactions on Nuclear Science 59 (2012) 3194-3200
A. Billebaud, A. Kochetkov, S. Chabod, X. Doligez, G. Lehaut, F.-R. Lecolley, J.-L. Lecouey, N. Marie, F. Mellier, V. Bécares, D. Villamarin, G. Vittiglio, H.-E. Thyébault, W. Uyttenhove, J.WagemansFREYA project, 7th EURATOM FP-Contract #269665. Deliverable 1.1: Current subcritical core results, 2013.
S.Di Maria, A. Kochetkov, G.Mila, S.Argiro, M.Carta, F. Gabrielli, G. Vittiglio, S. Chabod, P. Gajda, N. Marie, W. Uyttenhove, G. Lehaut, A. Billebaud, X. Doligez, F.-R. Lecolley, J.-L. Lecouey, V. Bécares, D. Villamarin, Y.RomanetsFREYA project, 7th EURATOM FP-Contract #269665. Deliverable 1.2: Deep subcritical experiments, 2013.
Publication
Experimental Results From the VENUS-F Critical Reference State for the GUINEVERE Accelerator Driven System ProjectUyttenhove W., Baeten P., Ban G., Billebaud A., Chabod S. et al.IEEE Transactions on Nuclear Science 59 (2012) 3194-3200
A. Billebaud, A. Kochetkov, S. Chabod, X. Doligez, G. Lehaut, F.-R. Lecolley, J.-L. Lecouey, N. Marie, F. Mellier, V. Bécares, D. Villamarin, G. Vittiglio, H.-E. Thyébault, W. Uyttenhove, J.WagemansFREYA project, 7th EURATOM FP-Contract #269665. Deliverable 1.1: Current subcritical core results, 2013.
S.Di Maria, A. Kochetkov, G.Mila, S.Argiro, M.Carta, F. Gabrielli, G. Vittiglio, S. Chabod, P. Gajda, N. Marie, W. Uyttenhove, G. Lehaut, A. Billebaud, X. Doligez, F.-R. Lecolley, J.-L. Lecouey, V. Bécares, D. Villamarin, Y.RomanetsFREYA project, 7th EURATOM FP-Contract #269665. Deliverable 1.2: Deep subcritical experiments, 2013.
Fig. 7: Correlation plot of the PMT at different pressure in CF4.
35
Medical and industrial applications
The "Medical and Industrial Applications" team is involved in dosimetry measurements for medical and industrial purposes since its
creation. For eight years the group is strongly involved into the development of beam monitors and carbon fragmentation studies forhadrontherapy.Hadrontherapy consists in irradiating cancerous tumours with light nuclei such as proton or carbon ions. Proton therapy is now widely spreadworldwide. Carbon therapy is growing in importance. To be as efficient as possible in irradiating the tumour, all physics and biologicalprocesses which may occur during the treatments must be kept under control. A specific software, the Treatment Planning System or TPS, isused to define the machine parameters for a given patient, pathology and accelerator. Once these parameters are determined, different set-ups are necessary to control the irradiation process. Nuclear physicists can contribute to hadrontherapy in two ways: by optimizing the dosecalculation module of TPS by studying the physical processes involved in the irradiation process ; by designing and building devices which canhelp to monitor the beam and which may allow controlling the dose deposition in the patient.The "Medical and Industrial Applications" team is also strongly involved in the ARCHADE project. This centre will be dedicated to the medical,biological and physical research in carbon-therapy and will be located at Caen. The group contributes to FRANCE-HADRON which gathers allthe scientific terms in medicine, biology and physics which contribute to the development of hadrontherapy in France.
G. Boissonnat*, J. Colin, D. Cussol, J. Dudouet*, J.M. Fontbonne, M. Labalme, S. Salvador
*PHD students
Beam monitors
The "Medical and Industrial Applications" team is developing beam monitors for the radio-biology experiments and for
treatment centres.
The use of swept pencil beams is more and more common in proton-therapy. It consists in delivering the dose by scanning
the tumour with several beam spots. Each spot corresponds to a given beam location, energy and fluency. The main
advantage compared to a passive beam dose delivery which uses beam range shifters and boluses to conform the dose to
the tumour geometry is that less matter is set in the beam and hence less secondary particles (mainly neutrons) are
produced. The price to pay is that the beam delivery is more complex. The correlations between the beam fluency, its
energy and location have to be accurately controlled all along the irradiation. The beam monitor has to be as transparent
as possible in order to minimize its disturbance on the beam (angular spreading, intensity attenuation, energy diminution).
36
In order to minimize the irradiation time during proton-therapy treatments, the trend is to increase proton beam intensities.
The former IC2/3 beam monitor is not well suited anymore. In collaboration with the Ion Beam Applications (IBA) Company,
new studies have been initiated to design and build a proton beam monitor for high intensities up to 109 ions per second.
This is the subject of the PhD thesis of G. Boissonnat.
A beam monitor for radio-biology experiments at GANIL has also been developed and tested at GANIL in September 2013
in the framework of the FRANCE-HADRON collaboration. This beam monitor called DOSION III is an adaption of the IC2/3
beam monitor for GANIL beams.
The "Medical and Industrial Applications" team is also studying the fragmentation processes of carbon ions which
contribute to spread the dose deposition beyond the Bragg peak.
Although hadrontherapy has an obvious ballistic advantage compared to conventional radiation therapies, fragmentation
processes may reduce this advantage. They occur when a projectile hits a nucleus present in the tissues. Secondary
fragments produced by this interaction are much lighter and have a velocity close to the velocity of the projectile. As a
result, the secondary particles have a longer range and deposit some dose in and beyond the Bragg peak of the initial
projectile.
The effect of the nuclear fragmentation process is twofold. The number of projectiles which do not experience a nucleus-
nucleus collision decreases strongly with respect to the penetration depth. Only one half of the initial carbon projectiles at
290 MeV/u reaches the maximum range. As a consequence, the dose deposition at the Bragg peak is strongly influenced
by the nuclear reaction cross section. The other effect of the fragmentation process is the appearance of a tail beyond the
Bragg peak. This so called "fragmentation tail" is mainly due to protons and alpha particles having a longer range. In
addition, the secondary fragments may have different biological effects (cell death, mutation rates and metabolic changes)
according to their nature.
In order to compute accurately the dose deposition and the resulting biological effects, it is necessary to have an accurate
knowledge of the fragmentation process of the projectile in human tissues. The ideal situation would be to have a valuable
model which could predict the production rates of secondary particles and their angular and energy distributions.
Uncertainties on the dose calculations are dominated by the uncertainties on fragmentation cross sections and on nuclear
reaction models.
Two experiments have been performed in May 2008 and in May 2011 with the ECLAN reaction chamber at the GANIL G22
beam line. These experiments have been performed in the framework of the GDR MI2B and in collaboration with the IPHC
Strasbourg, IPN Lyon and SPhN Saclay. The carbon energy was 95 MeV/u for both experiments. A schematic view of the
May 2011 experimental set-up is shown on Fig. 1. It included five three-layer ∆E/∆E/E telescopes for charged particles
detection. The telescopes were fixed on rotating stages of the ECLAN chamber. This allowed covering angles ranging
from 4° to 70°. For the may 2008 experiment, six PMMA targets (C5H8O2; d=1.19 g/cm3) of different thicknesses: 5, 10, 15,
20, 25 and 40 mm were used.
For the May 2011 experiment, the experimental set-up was very similar and thin C, CH2, Al, Al2O3 and Ti target were used.
The nuclear reaction cross sections and the fragments production rates for H, C, O and Ca (close to Ti) nuclei have been
extracted from this experiment. These nuclei are the most abundant nuclei in human tissues (more than 90%). This
experiment used the FASTER acquisition system. The measurements for a thin PMMA target have also been performed
for cross-checking. In September 2013 at GANIL, a complementary experiment has been performed in the framework of
the FRANCE-HADRON collaboration to measure the secondary fragments production cross sections at 0° for carbon ions
at 95 MeV/u colliding thin C, CH2, Al and Ti targets. The particle identification was done by using the standard ∆E/E
technique.
Fragmentation studies
Fig. 1: Schematic view of the experimental set-up of the May 2011 experiment at GANIL.
37
The results of the May 2008 experiment showed that none of the nucleus-nucleus collision models implemented in
GEANT4 (Binary Intranuclear Cascade, Quantum Molecular Dynamics, Intra Nuclear Cascade) are able to reproduce the
experimental data. The thin target experiments are best suited to constrain models since the fragmentation process occurs
in a very small energy range. This is the PhD thesis subject of J. Dudouet. Angular distributions of some fragments are
presented on Fig. 2. The double differential cross sections have been obtained with a good accuracy (~5% to 10%) for
almost all isotopes lighter than carbon nucleus. It has also been shown that the cross sections for composite targets can be
obtained within 5% accuracy by combining the cross sections obtained from individual nuclei. GEANT4 nucleus-nucleus
collision models have been compared to the experimental data. As for the thick target experiments, none of these models
are able to reproduce all the experimental data. The experimental data have been given a free-access on a web site
(http://hadrontherapy-data.in2p3.fr/).
The group is also participating to the FIRST European collaboration, which has measured C-C reactions at 400 MeV/u.
Particle charge identification using the time-of-flight wall of the 2011 experiment at GSI Darmstadt has been done in our
group.
Moreover, the preliminary design of an experimental set-up called FRACAS (FRAgmentation du CArbone et Sections
efficaces) for the ARCHADE centre has been done. It will consist of a time-of-flight wall for particle charge identification.
The mass measurement will be done by means of a magnet and tracking detectors located before and after the magnet.
This set-up should be efficient for the whole energy range of medical interest, i.e. from 80 MeV/u to 400 MeV/u. The
selection of the best suited materials and detection techniques for all these elements is under progress in collaboration with
the IPHC Strasbourg.
The group is also strongly involved in the FRANCE-HADRON collaboration. We are leading the Working Package 2
"Improving treatment planning in hadron-therapy”, and are members of the management committees. The management of
the GANIL beam time for the experiments performed in September 2013 has been done by the group.
Fig. 2: Angular distributions of differents fragments for a carbone projectile at 95 MeV/u hitting a thin carbon target.
The dose measurements on workers manipulating nuclear wastes are of great importance. The contribution of low energy
gamma and X rays (E<60 keV) to the global dose is not yet well measured. In the framework of the collaboration between the
PIERCAN company and the LPC Caen, the "Medical and Industrial Applications" team has performed simulations and
measurements to characterize the protection of gloves. In the framework of the collaboration between AREVA MELOX
company and the LPC Caen, the "Medical and Industrial Applications" team has performed a prototype of a new dosimeter
able to measure the dose on a large range in energy for nuclear workers. Two patents have been submitted.
Collaboration with industry
38
Publications
Proton computed tomography from multiple physics processesBopp C., Colin J., Cussol D., Finck C., Labalme M. et al.Physics in Medicine and Biology 58 (2013) 7261
Double differential fragmentation cross-section measurements of 95 MeV/u 12C on thin targets for hadrontherapyDudouet J., Juliani D., Angelique J.C., Braunn B., Colin J. et al.Physical Review C 88 (2013) 024606
Comparison of two analysis methods for nuclear reaction measurements of 12C +12C interactions at 95 MeV/u for hadrontherapyDudouet J., Juliani D., Labalme M., Angélique J.C., Braunn B. et al.NIM A 715 (2013) 98-104
Benchmarking GEANT4 nuclear models for carbon-therapy at 95 MeV/ADudouet J., Cussol D., Durand D., Labalme M.To be published in Physical Review C
Characterization and performances of a monitoring ionization chamber dedicated to IBA-universal irradiation head for Pencil BeamScanningCourtois C., Boissonnat G., Brusasco C., Colin J., Cussol D. et al.NIM A 736 (2014) 112-117
Publications
Proton computed tomography from multiple physics processesBopp C., Colin J., Cussol D., Finck C., Labalme M. et al.Physics in Medicine and Biology 58 (2013) 7261
Double differential fragmentation cross-section measurements of 95 MeV/u 12C on thin targets for hadrontherapyDudouet J., Juliani D., Angelique J.C., Braunn B., Colin J. et al.Physical Review C 88 (2013) 024606
Comparison of two analysis methods for nuclear reaction measurements of 12C +12C interactions at 95 MeV/u for hadrontherapyDudouet J., Juliani D., Labalme M., Angélique J.C., Braunn B. et al.NIM A 715 (2013) 98-104
Benchmarking GEANT4 nuclear models for carbon-therapy at 95 MeV/ADudouet J., Cussol D., Durand D., Labalme M.To be published in Physical Review C
Characterization and performances of a monitoring ionization chamber dedicated to IBA-universal irradiation head for Pencil BeamScanningCourtois C., Boissonnat G., Brusasco C., Colin J., Cussol D. et al.NIM A 736 (2014) 112-117
Patents
J-M. Fontbonne, C. Fontbonne, J. Colin, J. JehannoProcédé d’asservissement du gain et du zéro d’un dispositif de comptage de photons à pixels multiples et système de mesure de lumière mettant en œuvre ce procédéDépôt Fév. 2013 under examination
J-M. Fontbonne, J. Colin, C. Fontbonne, J. JehannoProcédé de mesure de dose au moyen d’un détecteur de rayonnements, notamment d’un détecteur de rayonnements X ou gamma, utilisé en mode spectroscopie et système de mesure de dose utilisant ce procédéDépôt Fév. 2013, under examination
39
Precise correlation measurements in nuclear beta decay
High resolution study of low energy charge exchange collisions with a MOT (magneto-optical trapped) target
Towards a new measurement of the neutron Electric Dipole Moment (EDM)
Search for neutrinoless double beta decay
RESEARCH
FUNDAMENTAL INTERACTIONS
40
GRoup “Interactions FOndamentales et nature du Neutrino” (GRIFON)
The GRIFON group at LPC Caen is involved in four experimental research activities :
LPCTrap: search for exotic couplings in nuclear weak decay processes, MOT: High resolution studies of atomic collisions in a MOT, nEDM: measurement of the neutron electric dipole moment, NEMO-3/SuperNEMO: search for neutrinoless double beta decay.
Each member of the group participates to one or two of these experimental programs. The instrumental and technical know-how and specificskills acquired in these research activities are often shared within the GRIFON group: detection of electrons in the MeV energy range withPMT-based optical modules (LPCTrap/SuperNEMO), electric and magnetic fields computing (nEDM/SuperNEMO/LPCTrap), Monte-Carlo simulations (SuperNEMO/LPCTrap), parallel computing (nEDM/LPCtrap). Most of these research activities are maintained within the framework of internationally recognized collaborations. The experi-mental setups are hosted in first-class facilities :
Institut Laue-Langevin (ILL), Paul Scherrer Institute (PSI), GANIL/SPIRAL, Laboratoire Souterrain de Modane (LSM), Center for Nuclear Physics and Astrophysics (CENPA, Seattle), CERN/ISOLDE.
For all these projects, the LPC Caen occupies a prominent position with well identified responsabilities and recognized skills.
G. Ban, C. Couratin*1, D. Durand, X. Fabian*1, X. Fléchard, B. Guillon, V. Hélaine*2, T. Lefort ,Y. Lemière, A. Leredde*3, E. Liénard, F. Mauger, O. Naviliat4, G.Quéméner
Experimental facilities : Institut Laue-Langevin (ILL), Paul Scherrer Institute (PSI), GANIL/SPIRAL, Laboratoire Souterrain de Modane (LSM),
CENPA (Seattle), CERN/ISOLDE.
*PHD students1 LPCTrap, 2 nEDM, 3 MOT4 NSCL/MSU East Lansing
41
The LPCTrap setup installed at GANIL/LIRAT has been built to measure with high precision beta-neutrino angular
correlation parameters, a, in nuclear beta decays [Ban13]. Such measurements provide the most stringent limits on exotic
Scalar (S) or Tensor (T) type contributions to the nuclear weak decay process. Precisions at a level of at least 0.5% are
needed to improve the current sensitivity to these exotic weak interaction components. In addition, in the case of a mirror
decay, the measurement of a enables to precisely determine the mixing ratio, ρ, between the Gamow-Teller (GT) and the
Fermi (F) components in the transition. Combined with the Ft value, this mixing ratio can be used to determine accurately
Vud, the first element of the Cabibbo-Kobayashi-Maskawa (CKM) matrix. Again, measurements of a at a precision level of
at least 0.5% in some selected mirror decays for which the parameters involved in the Ft values are accurately known
would enable to reach a precision on Vud equivalent to the current precision obtained from the usual pure F transitions.
In the LPCTrap setup, the radioactive ions are confined in a transparent Paul trap and the correlation parameter, a, is
precisely inferred from the time of flight of the low energy recoiling ions detected in coincidence with the beta particles.
Moreover, the recoil ion spectrometer gives access to the charge state distributions of daughter ions stemming from 1+
ions decay. The setup allows a very strong control of the systematic effects.
The 6He pure GT decay is the first transition studied with LPCTrap [Cour13]. The last experiment was performed in 2010.
The recoil spectrometer enabled to measure for the first time the charge state distributions of the recoiling 6Li ions
produced after the β decay of 6He1+ ions. An electron shake-off probability, Pexp=0.02339(36), was deduced from the data
[Cour12]. The value is in perfect agreement with simple quantum mechanical calculations, Pth=0.02322, based on the
sudden approximation, which has then been proved to be well suited for such a pure electron shake-off process. A
preliminary value has been estimated for the angular correlation parameter, a=-0.3338(26)stat, but the realistic simulations
needed to extract a have still to be refined to carefully manage the relevant parameters of the experiment. The number of
recorded events, 1.2×106, should enable to determine a with an unprecedented statistical accuracy of 0.0015 (0.45% in
relative precision).
As far as the 6He decay is concerned, the team now contributes in a new experiment involving magneto-optical traps
(MOT) and installed at CENPA, Seattle [Knec13]. Our main contribution is the development of the recoil ion detector and
the installation of the acquisition system FASTER developed at LPC Caen (see section "Administration and technical
departments, Instrumentation" of the present report). The goal of the experiment is to reach the precision level of 0.1% in
the measurement of a.
The apparent success of 6He experiment has favoured the upgrade of LPCTrap to make it operational with masses heavier
than 6 and, in June 2011, the setup has been commissioned with the 35Ar1+ beam delivered by SPIRAL. The 35Ar nuclei
decay through a mirror transition dominated by the F component (93%). A total of 4×104 good events was recorded in 32
hours of data taking. This enabled to measure for the first time the charge state distribution of the recoiling 35Cl ions
[Cour13b], which is in excellent agreement with theoretical values (see table 1).
This analysis has highlighted the important role of Auger processes in electronic rearrangement of such ions. The number
of 35Cl atoms produced during the experiment was deduced from the number of beta particles detected in singles and the
overall absolute detection efficiency for ions.
This estimate leads to 72(10)% of neutral 35Cl recoils, which is also consistent with the 73.9% ratio obtained from the
theoretical calculations.
Precise correlation measurements in nuclearbeta decay
In collaboration with :LPC Caen, CIMAP Caen, GANIL Caen, IKS/KUL Leuven, NSCL/MSU East Lansing,
Univ. Granada, CENPA Seattle, CELIA Bordeaux, Argonne National Laboratory, NCNR Warsaw
Charge Expt. results Calculationwith Auger
Calculationwithout Auger
1234>4
74.75 (1.07)17.24 (0.44)5.71 (0.27)1.58 (0.21)0.71 (0.18)
74.3716.986.031.790.82
87.0711.920.950.05<0.002
Table 1: Experimental ion charge-state relative branching ratios (%) compared to calculations with and without Auger ionizations.
42
The real experiment with 35Ar was performed in June 2012. The total efficiency of LPCTrap (transmission & trapping:
0.38%), has enabled to record 1.5×106 real coincidences in one week (Fig.1) [Ban13]. This statistics should allow a
determination of a with an absolute uncertainty of 0.0018 (~0.2% in relative precision). Assuming a systematic uncertainty of
the same order than the statistical one, the final result would constitute the most precise value ever obtained in a beta-
neutrino angular correlation measurement. The analysis is ongoing [Fabi]. As far as the 35Ar decay is concerned, the team
was also involved in WITCH runs at CERN/ISOLDE [Brei12]. Again our main contribution was dedicated to the recoil ion
detector and the installation of the acquisition system FASTER developed at LPC Caen.
In September and October 2013, the commissioning run and a first experiment were performed with 19Ne which mainly
decays through a mirror transition to the ground state of 19F (BR=99.9858(20)%). To get rid of the huge contamination of
stable molecular ions with mass 19 in 1+ charge state coming from the ECS source of SPIRAL, the beam lines were tuned in
2+ charge state. This enabled to run the experiment, but with a loss of a factor of 3 in the RFQ efficiency. Nevertheless,
even with this charge state, the contamination of the beam with 19F2+ remained important and saturated the RFQ, limiting the
effective number of trapped radioactive ions. Finally a total number of 1.3×105 coincidences were recorded during 4 days of
data taking (Fig. 2), which remains reasonable considering that the half-life of 19Ne is ten times larger than in the case of35Ar. This statistics will enable to determine the precise charge state distribution of the recoiling 19F ions. A comparison
between fig. 1 and 2 shows that the higher charge states are less favored for 19F ions, which is consistent with a lower
probability of Auger effects in the decay of 19Ne1+ ions, as predicted by the theoretical calculations [Lien12]. This first
analysis will be completed in the coming months. The statistics collected during the experiment will also enable to analyze
systematic effects in the determination of a in some extreme conditions linked to 19Ne as the recoil maximum kinetic energy
is the lowest in this case.
Counts/channel
As far as the 19Ne decay is concerned, the team was also involved in a precise T1/2 measurement performed at GANIL
[Ujic12]. Here our main contribution was the installation of the acquisition system FASTER.
In conclusion, we have collected a large amount of data concerning three different transitions. The next year will be
dedicated to the complete analysis of these data, to extract precise values of the beta-neutrino angular correlation
parameters in the three cases. This will also enable to design an upgraded LPCTrap setup, to continue weak interaction
studies with the new beams expected in the upgrade of SPIRAL, first at LIRAT and later in the DESIR hall.
Fig.1: Experimental time-of-flight distributions of 35Cl n+ ions produced by the β decay of 35Ar1+ ions confined in the Paul trap.
0 5 100
10000
20000
30000
F3+
F2+
Co
un
ts
ToF (µs)
~1.1x105 good events
F+
Fig. 2: Raw experimental time-of-flight distributions of 19F n+ ions produced by the β decay of 19Ne1+ ions confined in the Paul trap.
43
Laser cooling and trapping of atomic samples in a MOT (Magneto-Optical Trap) is now a first step for many exciting and
innovating experiments in atomic physics such as Bose-Einstein condensate formation and superfluidity studies,
electromagnetically induced transparency, photoassociation, quantum information, etc… Another possible application is the
confinement of radioactive atoms produced by nuclear reactions. The cold cloud of trapped exotic atoms constitutes a very
clean source to perform precision measurements in nuclear β decay: using 6 laser beams and a quadrupolar magnetic-field,
the atoms are held in a small volume, almost at rest and in a high vacuum, which allows the detection in coincidence of the
decay products using surrounding detectors [Knec13]. Moreover, they can be easily polarized using lasers for correlation
measurements in the decay of polarized nuclei [Pitc09].
Having for final objective the installation of such a device on the future DESIR facility at SPIRAL2, the LPC has designed and
built a MOT for stable rubidium atoms. With stable atoms, the nice properties of a MOT mentioned above can be used to
provide a cold atomic target for the study of ion-atom collisions at low energy. In such experiments, the most effective
technique is the recoil ion momentum spectroscopy (RIMS) [Dorn00]. It gives access to the main observables of the collision
(the Q of reaction and projectile scattering angle) through the measurement of the ionized target recoil momentum. The
momentum change due to the collision being very small (a fraction of a.u.), the resolution is usually limited by the temperature
of the target. The Rb target provided by the MOT is a cloud of about 107 atoms confined in a 1 mm3 volume at a temperature
below 200 mK. Such a low temperature does not limit the resolution on the momentum measurement and the coupling of a
Rb MOT with RIMS (called MOTRIMS) results in very high precision experiments. The MOTRIMS setup designed and built at
the LPC is shown in the fig. 3. It includes transverse extraction of the recoil ions with a 3D focusing electrostatic spectrometer,
and a fast switch-off of the trapping B-field during data counting [Blie08].
High resolution study of low energy charge exchange collisions with a MOT (magneto-optical trapped) target
In collaboration with CIMAP (Caen) and CELIA (Bordeaux)
Fig. 3: Schematic view of the setup (see text and ref. [4] for details)
MOTRIMS can in principle be employed, as in
conventional RIMS, to probe a multitude of
scattering dynamics [Dorn00]. In a first step, we
focused on single charge transfer in low energy
Na++87Rb(5s,5p) collisions. The performances of
the device allowed the detection of weakly
populated charge transfer channel (contributing to
less than 1% of the total cross sections), and
provided accurate relative cross sections for the
active channels, along with their associated
distributions in projectile scattering angle. The high
resolution on the scattering angle measurement
(~50 mrad) has even enabled to resolve the
predicted diffraction-like oscillations due to the
limited range of impact parameters leading to
charge exchange process. The results have been
then used to test and refine molecular close-
coupling (MOCC) calculations performed at the
CELIA in Bordeaux with unprecedented precision.
This joint theoretical/experimental study was
published in 2012 [Lerr12].
44
In a second step, we have used the opportunity to prepare the target with lasers to investigate the case of charge exchange
scattering between Na+ ions and oriented Rb(5p±1) atoms. It is known from previous studies on similar systems that the
differential cross sections (DCS) in projectile scattering angle for charge exchange exhibit asymmetries related to the
coherence of the capture process (Fig. 4). However, most of these previous studies called for more precise measurements in
order to reveal the exact angular dependence of the DCS and associated coherence parameters. In this respect, Na+ + Rb
collisions are particularly challenging since the projectiles are scattered in very forward directions [Lerr12]. To apply the
experimental technique to the case of oriented 5p states, several improvements of the setup have been achieved. An
additional laser, with circular polarized light (right or left) could be shined on the trapped atoms to prepare the target in a (52p3/2,
F=3, mF =+3) state or a (52p3/2, F=3, mF=-3) state when the trapping magnetic-field is switched-off. Helmholtz coils were also
added to the setup to provide a weak (4 Gauss), constant and homogeneous magnetic-field that defines a vertical polarization
axis. Finally, two different diagnostics were developed to measure the polarization efficiency and the polarization rate. We
found that more than 95% of the atoms were oriented within a time interval shorter than 5 µs.
Fig. 4: Schematic representation of the experiment. A homogeneous magnetic field Bh defines the quantization direction (z axis), and optical pumping leads to magnetic sublevels of the target state with well defined hyperfine quantum numbers mF, depending on the handedness of the laser pulse. The initial and final states are therefore quantized in the (x, y, z) reference frame.
The Na+ ions impinge on the oriented target with velocity v and impact parameter b, and the scattered projectile distribution is characterized by the spherical angles (q,j) in the (xcol, ycol, zcol) scattering frame.
Experiments were performed with oriented (52p3/2, F=3,
mF=±3)≡Rb(5p±1) targets at E=5, 2, and 1 keV. The capture
channels of interest Na+ + Rb(5p±1) à Na(nl) + Rb+ were easily
identified and selected using the recoil-ion-momentum
component parallel to the projectile beam axis. Precise DCS in
projectile scattering angles θ and ϕ (Fig. 3) were then derived
from the transverse momentum components. We present in
Figs. 5 (a - f) the weighted DCS sin(θ)sp+1à3p(θ,j) associated with
the principal Na+ + Rb(5p±1) to Na(3p) + Rb charge exchange
reaction, in terms of its four main contributions to which we refer
to as left (ϕ=0), up (ϕ=π/2), right (ϕ=π), and down (ϕ=3π/2)
(Fig. 4). These contributions are displayed as functions of Eθ,
which is related to the impact parameter b.
We observe in Fig. 5 that the up and down contributions to the
DCS are symmetric, whereas the left and right ones exhibit
strong asymmetry. As may be seen from Fig. 3, the rotation of
the electron flow inherent to the initial oriented state breaks the
symmetry of left (y>0) and right (y<0) scatterings while it
preserves the up-down symmetry because of reflection
symmetry with respect to the (x, y) plane. To proceed more
quantitatively, the quantum-mechanical origin of the asymmetry
has been investigated using adequate MOCC calculations
(Fig. 5). The asymmetries in the DCSs, observed here with
unprecedented resolution, were then used to access to the
related coherence properties of the capture process in the
different charge exchange channels. This work has enabled not
only the theoretical description to be improved but also marked
out the limits of the single-active-electron and frozen-core
approximations. More details about this work can be found in
[Lerr12b].
Fig. 5: Weighted DCSs for the charge exchange reaction
Na+ + Rb(5p+1) à Na(3p) + Rb+ at E=1 [(a),(b)], 2
[(c),(d)], and 5 [(e),(f)] keV, as functions of Eθ. The
histograms are the measurements, while the continuous
(red) lines correspond to MOCC calculations.
45
Towards a new measurement of the neutron Electric Dipole Moment (EDM)
In collaboration with: PTB (Berlin, Germany), LPC (Caen, France), JUC (Crakow, Poland), HNI (Crakow, Poland), JINR (Dubna, Russia), LPSC (Grenoble, France), University of Kentucky (Lexington, UK), KUL
(Leuven, Belgium), CSNSM (Orsay, France), Sussex University (Brighton, SU), PSI (Villigen, Switzerland) and ETH (Zürich, Switzerland).
Motivations
Searches for permanent electric dipole moment (EDM) of particles are considered to be among the most important particle
physics experiments at low energy since a non-zero value may reveal non-standard sources of CP violation and physics
beyond the standard model (SM). More than 30 experiments are currently running or planned worldwide aiming at measuring
the EDM of fundamental particles or systems such as electrons, neutrons, muons, atoms, molecules, etc... Beside the possible
implications on the SM, the discovery of new CP violation sources is also required to explain the baryon asymmetry of the
universe (BAU) [Sak67].
In this context, searches for the neutron EDM (nEDM) have been started in the 50’s and have been pursued over more than 60
years lowering the nEDM upper precision limit down to <3×10-26 e·cm (90% CL) [Bak06]. The δ−induced nEDM predicted by
the SM is 10-32±1 e·cm while the SM extensions predict a neutron EDM in the range of 10-26-10-28 e·cm. Therefore, the next
generation of neutron EDM experiments should be able to validate or exclude such models.
The current limitation on the measurement precision is statistical. As a result, all the new nEDM projects (7 over the world) are
coupled to the building of high intensity ultra-cold neutron (UCN) sources. At the Paul Sherrer Institute (PSI) in Switzerland, the
nEDM experiment is taking place close to a spallation-induced UCN source which has recently been launched. Very first UCN
were delivered in December 2010 and the UCN source commissioning was started in 2011.
nEDM experiment status
During the last two years, UCN beam time has been shared between UCN source studies, nEDM spectrometer tuning and
nEDM data taking. The experiment status is the following.
Despite an increase of 40% since 2011, the UCN flux produced by the PSI source remains 15 times lower than initially
anticipated. Reasons are not fully understood and studies are still ongoing in order to recover the lack of UCN production. On
the other hand, the spectrometer is basically working. The current statistical sensitivity is 2.8×10-25 e·cm per day i.e. the best
sensitivity achieved so far with the apparatus. However, the apparatus reliability is not optimal and will be further improved in
order to increase the number of data taking days per year. From 2012 and 2013, the integrated statistical sensitivity is at best
equal to 5.9×10-26 e·cm. The analysis is still ongoing and is part of V. Hélaine’s thesis. Systematic errors are quoted at the level
of 4×10−27 e·cm i.e. well below the statistical uncertainty. In these conditions, continuing the data taking for 3 more years will
result in a new nEDM measurement at a level comparable to the present limit but with a better control of systematic effects. If
the full factor 15 in the UCN source intensity is recovered, we expect to improve the limit by a factor 4.
In order to significantly improve the statistical sensitivity, a new spectrometer (n2EDM) is under study. A statistical precision 5
times better than the former one is foreseen. Combined with the current UCN source performances, a limit of 5×10-27 e·cm
could be achieved after 4-5 years of data taking, i.e. in about 10 years. Assuming the UCN source will reach its nominal
performances, the 10-28 e·cm range will start to be explored. Beside the contribution to the running of the experiment itself, the
LPC Caen is in charge of the development of a new spin analyzing system, the UCN detection and the 3D magnetic field
measurements.
Set-up of a new U-shape Simultaneous Spin Analyser (USSA)
Based on GEANT4 simulations, a U-shape simultaneous spin analyser system has been built and tested at PSI (see the
left panel of Fig. 6). The aim of such a new device is to perform UCN counting and to be able to simultaneously measure both
UCN spin components. It will replace the current sequential spin analyser which induces UCN losses and depolarizations. A
second NANOSC detector and a dedicated FASTER acquisition have been developed for the USSA. This project is part of the
V. Hélaine’s thesis.
Fig. 6: left panel: picture of the simultaneous spin analyser (USSA);
right panel: neutron frequency measurement performed with the
USSA.
46
The USSA has been tested and compared to the current system for standard nEDM runs. A preliminary measurement of the
nEDM statistical sensitivity is very promising showing an increase of 18.2(6.1)% with respect to the sequential device. As a
result, the USSA has been installed below the nEDM spectrometer for the future nEDM data taking. Such results have to be
further confirmed in 2014.
Development of a new UCN gas detector
Investigations about a novel UCN gas detector have been started. Two approaches are under study: a Micro-Pattern
Gaseous Detectors (MPGD) based on the GEM (Gas Electron Multiplier) technology and a scintillating gas detector using
one or two PhotoMultipliers Tubes (PMT). The aims are three fold: decrease the background sensitivity, increase the
detection efficiency and handle large counting rates up to106 counts/s.
A generic detector chamber has been built (see the left panel of Fig. 7). The vacuum tightness has been tested and a
pressure limit down to 1.5×10-7 mbar has been reached. The GEM version of the detector has been characterized using an
alpha source for two gases: ArCO2 and CF4. A Maximum pulse duration of 150 ns has been measured, which fulfills the
counting rate requirement. No discharge was observed for gains up to 8×103.
The scintillating version of the detector has been tested with a CF4/4He gas mixture with a partial 4He pressure varying from
0% up to 10%. Using an alpha source and one photomultiplier, about 50 photons have been collected for a deposited
energy of 6 MeV. The next step is the design of a new detector with two PMTs for the light readout. The goals are two fold:
increase the photon collection efficiency and suppress the background by coincidence counting technique.
Magnetic field mapping
A precise knowledge of the 3D magnetic field inside the nEDM apparatus is of crucial importance for correcting some
systematics effects (see the previous progress report for more details). In order to measure the field components, we use
either a 3D fluxgate or a vector caesium magnetometer. They are positioned on a new mapping device designed and built at
LPC as shown in Fig. 8. To avoid field induced by eddy currents, this mapper is made almost fully out of non-conducting
materials (PEEK, POM and ceramics). This device allows mapping a cylindrical volume by moving the probe inside the
nEDM vacuum tank (radial, vertical and azimuthal motions). Special care has been taken to ensure mechanical
reproducibility.
A mapping campaign has been performed during the winter 2013 with this device. One of the measured maps is shown in
Fig. 8 where a magnetic anomaly is seen at the front left side of the nEDM spectrometer. Further maps will be performed in
2014 looking for such magnetic pollution in order to remove them.
Fig. 7: left panel: detector chamber picture; right panel: identification chart for the scintillating version of the detector.
Fig. 8: left panel: picture of the new mapper into the vacuum chamber; right panel: field map of the spectrometer inside.
47
Motivations
Many extensions of the Standard Model provide a natural framework for neutrino masses and lepton number violation. In
particular the see-saw mechanism, which requires the existence of a Majorana neutrino, naturally explains the smallness of
neutrino masses. The existence of Majorana neutrinos would also provide a natural framework for the leptogenesis process
which could explain the observed baryon-antibaryon asymmetry in the Universe. The observation of neutrinoless double-β
decay (0νββ) would prove that neutrinos are Majorana particles and that lepton number is not conserved. The isotopes for
which a single-β is energetically forbidden or strongly suppressed are most suitable for the search of this rare radioactive
process. The experimental signature of 0νββ decays is the emission of two electrons with total energy (ETOT) equal to the Q-
value of the decay (Qββ). The NEMO-3/SuperNEMO international collaboration has maintained an experimental program of
research of the (0νββ) process for about 20 years. Currently, the LPC NEMO group is involved in two projects: the NEMO-3
experiment and the SuperNEMO project.
NEMO3 final analysis
After 8 years of data collection, the NEMO-3 detector has been stopped in february 2011 and dismantled at the Modane
Underground Laboratory (LSM, Fig. 9). The NEMO collaboration now does the final analysis with the full statistics: ~35 kg⋅y of100Mo and ~4.5 kg⋅y of 82Se.
From 2007, the NEMO group at LPC Caen has been in charge of the quality survey of the NEMO-3 calorimeter energy
calibration using the laser system. This task has been completed in 2012 and the final set of quality parameters has been
delivered to the collaboration, corresponding to the individual survey of 2034 photomultiplier tubes (PMT) from 2003 to 2011.
This deliverable is now used by the collaborators responsible of the analysis. This work is critical because the search for the
(0νββ) process is very sensitive to the stability of the energy measurement. During 8 years of running, the majority of the 1940
PMTs have shown a very good stability (<1%) of their gain. However, a few percents of the PMTs had been observed with gain
fluctuations larger than what was acceptable (>2%). The laser survey system has been used to identify the PMTs with such a
problematic behaviour. This approach allows to reject these PMTs from the analysis and leads to elaborate a safe dataset,
particularly for the search of the (0νββ) process at high energy, where one wants to achieve the best signal/background ratio.
The limit obtained on the half-life of the (0νββ) process for 100Mo is T1/2(0nbb)>1.1×1024 y [Bong13]. This is the best result ever
obtained for this ββ isotope. In 2013, the group has been actively involved in the writing of the publication dedicated to the final
NEMO3 results of (0νββ) with 100Mo.
Search for neutrinoless double beta decay
Collaboration NEMO3/SuperNEMOLPC (Caen, France), IPHC (Strasbourg, France), LAL (Orsay, France), Idaho National Laboratory
(Idaho Falls, U.S.A.), ITEP (Moscow, Russia), UCL (London, UK), University of Manchester (Manchester, UK), JINR (Dubna, Russia), CPPM (Marseille, France), CENBG (Gradignan, France), LAPP (Annecy-le-Vieux, France),
IEAP (Prague, Czech Republic), University of Texas (Austin, U.S.A.), LSM (Modane, France), University of Warwick Coventry, (UK), Osaka University (Osaka, Japan), Saga University (Saga, Japan), FMFI
(Bratislava, Slovakia), LSCE (Gif-sur-Yvette, France), Imperial College (London,UK), Institut Universitaire de France (Paris, France), Jyväskylä University (Jyväskylä, Finlande), MHC (South Hadley, Massachusetts, U.S.A.),
Institute for Nuclear Research (Kyiv, Ukraine), Charles University (Prague, Czech Republic).
Fig. 9: Left: the NEMO-3 detector within the radon-free tent at LSM (2004). Right: a neutrinoless double beta decay candidate event in the NEMO-3 detector.
48
Fig. 10: The ETOT distribution for 100Mo in the NEMO-3 detector after 34.7 kg⋅y exposure. In the [2.8-3.2] MeV range (Qbb=3.034 MeV), 15 events have been observed. Low
radioactivity measurements, dedicated analysis and Monte-Carlo simulations have been used to predict 18 background events. The NEMO-3 experiment shows no evidence of
neutrinoless double beta decay.
Fig. 11: Left: Exploded view of the SuperNEMO demonstrator module: the central planar source frame is surrounded by two tracking chambers (2034 open drift cells working in Geiger regime) and two calorimeter walls (520 optical modules with low-radioactivity 8” PMTs). Right: the SuperNEMO demonstrator
will be installed in the LSM cavity in place of the NEMO-3 detector.
SuperNEMO experiment construction status
The SuperNEMO detector is the next generation experiment designed to search the neutrinoless double beta decay process
at the 1026 y sensitivity level (sensitivity to the effective Majorana neutrino mass: ~50 meV). The design of the SuperNEMO
experiment reuses and improves the NEMO-3 technology: it consists in 20 planar modules, each hosting about 5 kg of ββ
enriched isotopes. After a R&D program from 2005 to 2011 in which the LPC Caen has been strongly involved (BiPo1 and Bipo2
prototype detectors for the measurement of the radioactivity of the source foils, DAQ development, analysis and simulation
software, electronics development), the IN2P3 Scientific Council has validated a first phase of the project in 2011: the
SuperNEMO demonstrator module [CSIN2P3]. This module is now in construction (Fig. 11). The data collection will start in the
second semester of 2015 for 2.5 years. It will accomodate ~7 kg of 82Se and should reach a sensitivity of T1/2(0νββ)~6.5×1024 y.
This intermediate step is necessary to prove that the NEMO technology will be able to reach the target sensitivity with 20
modules and a 100 kg source of 82Se isotope. Several points will be addressed with the demonstrator:
the calorimeter energy resolution should be validated at the level of 8% FWHM at 1 MeV,
the source radiopurity should be measured at the level of 10 mBq/kg for 214Bi and 2 mBq/kg for 208Tl,
the radon (222Rn) contamination of the tracking chamber should be measured at the level of 0.15 mBq/m3.
The LPC Caen is involved in several working packages of the SuperNEMO project.
49
Readout and trigger electronics
The LPC Caen NEMO group leader is the scientific coordinator of the SuperNEMO electronics work package. He is
assisted by a senior engineer from LAL. This implies the management of five engineering and development teams: LPC Caen
(FEAStraduction enterinerT ASIC), LAL Orsay (calorimeter front end board and integration), University of Manchester (tracker
front end board), University of Osaka (DAQ) and LAPP Annecy. The group is therefore strongly involved in the elaboration and
design of the specifications of various core components of the SuperNEMO demonstrator front end electronics:
the specifications and design of the tracker front end board's ASIC (FEAST).
the specifications of the calorimeter front end board (with LAL)
the trigger system and strategy (with LAL)
the readout system and data format (with LAL)
In addition, the LPC Caen participates to the specification and architecture design of:
the DAQ system (with Osaka)
the Control and Monitoring System (CMS, with LAPP)
various interfaces (cabling, mechanics...)
Several tasks have been achieved in the 2012-2013 period:
the hardware architecture and specifications of the front end electronics integration scheme has been finalized. This
implies: 52 calorimeter front end boards for >700 channels, 57 tracker front end boards (>6000 channels), 6 control boards
(CB), 6 crates with their custom backplanes, 1 trigger board (TB), dedicated unified bus and protocols, interfaces (DAQ,
CMS, etc...),
the final batch of 150 FEAST chips has been delivered,
a new test bench had been produced to perform exhaustive tests of the FEAST ASIC in real readout conditions,
the specifications of the trigger system for both calorimeter and tracker front end board, as well as for the control board is
completed,
parts of the specifications and design of the readout have been done.
Software
The NEMO group has also a strong involvement in the development of the SuperNEMO simulation and data processing
off-line software. This task is organized in two main parts: the design and implementation of the generic multi purpose Bayeux
C++ library and the development of the software tools that are specific to the SuperNEMO project (SuperNEMO
demonstrator, BiPo3 detector): the Falaise C++ library.
The Bayeux library
A set of C++ library modules and companion applications has been designed to perform various core tasks of interest in
the making of nuclear and particle physics simulation applications: these contributions have been packaged in the Bayeux
library. This software package contains the following generic components in charge of:
data modelling, generic serialization and advanced I/O system, object factories,
data selection and data processing mechanisms(pipeline),
numerical tools,
generic geometry modelling (compatible with GDML/Geant4),
generic vertex generation for Monte-Carlo inputs,
generic event generation for Monte-Carlo inputs (radioactivy, ββ processes, etc...),
generic electro-magnetic field modelling,
generic Monte-Carlo simulation engine (based on Geant4).
Bayeux has been designed with genericity in mind and thus can be used in the context of many different experimental setups
(Fig. 12). It is now a rather mature and stable library.
Fig. 12: A simple detection setup modeled with the Bayeux library and used through the Geant4 engine to simulate the emission of 1 MeV electrons from a radioactive source. This simulation framework is fully parameterized by a set of human friendly configuration files (geometry, vertex generator, event generator, management of Geant4 session), without the need to write a single line of C++ code.
50
Its geometry modeling engine and Geant4 based simulation engine are used not only by the SuperNEMO collaboration to
simulate the SuperNEMO and BiPo3 detectors (see the Falaise library below) but also by some other experimental
projects: simulation of high purity germanium detectors (HPGe) for low radioactivity measurements at LSM, simulation of
the LPCTrap experiment. Some new projects have started to implement dedicated simulation tools using the core
functionalities of Bayeux (LPCCaen/IM2NP collaboration for the prediction of soft error rate in microelectronics components
and circuits). The use of the Bayeux library is also foreseen for educational purpose at the Université de Caen (nuclear
physics labs and teaching activities related to radiation protection).
The Falaise library
The Falaise C++ library is a collection of software dedicated to the SuperNEMO project. It implements the official
simulation and reconstruction tools for the SuperNEMO demonstrator module and the BiPo3 detector. This library uses
Bayeux as its foundation library. It is still under development and is currently integrating the SuperNEMO prototype code
written during the R&D phase of the SuperNEMO project. Falaise modules are:
SuperNEMO/BiPo3 simulation tools and application
Reconstruction tools and application
Analysis tools
Event display (Fig. 13)
The final design and software integration of Falaise has started in 2013 and will continue during 2014.
Magnetic coil
Our group is also responsible of the SuperNEMO magnetic coil: its study, its design, and finally its implementation at
the LSM Laboratory. Indeed, a magnetic field of about 20 to 35 Gauss along the vertical axis is needed to provide the
charge recognition and reject background events. The former NEMO-3 coil works perfectly during data collection; it was
simple, stable and robust. Moreover we could re-use most of its components, which reduces significantly the cost. Thus,
except minor changes (shape, size, etc...), it was decided to use a similar design for the SuperNEMO coil; NEMO-3
feedback, test with a prototype build at LPC Caen and magnetic field simulations serving as support to validate the final
demonstrator design.
Two of the ten panels of the NEMO3 coils were delivered at LPC Caen on February 2013. All elements have been sorted,
weighted, neatly cleaned, then reformed to built the reduced size prototype. It was thus a very useful tool to get it into one’s
head with mechanics and to validate the magnetic field computations. For his purpose, we use the code "Maentouch"
developped by Gilles Quemener for the nEDM experiment. This code, written in C++ in the ROOT software framework, is
based on boundary element methods. Magnetic field measurements show that we have a good understanding and control
of the magnetic field inside the coil (Fig. 14). In parallel, many tests have been done on the conductive contacts between
copper bars. In fact, it must present a large mechanical robustness and an electrical resistivity as low as possible to avoid
warm up of the detector. This prototype will now be used to test the SuperNEMO photomultiplier magnetic shieldings.
Fig. 13: A double-beta decay of 82Se simulated from the source foil of the SuperNEMO module displayed by the SuperNEMO 3D visualization program. The tracks of the two electrons emitted from the source foil are shown. The response of the drift cells and the calorimeter blocks are simulated too.
51
At present, the final mechanical design of the SuperNEMO coil is fixed. It will surround the entire detector (source foil, tracker
and calorimeter), with a developed circumference of about 17 m and a height of about 3.5 m. It consists on about 200 turns of
square copper wires of 10 × 10 mm square section, held together by isolating delrin pieces. About forty panels of iron (10 mm
thick) are use for back magnetic field. For detector access reasons, the coil will be split into panels connected together with
copper contact tubes. The complete coil has a mass of about 9 tons (~3.5 tons of high radio purity copper and ~5.4 tons of
ARMCO Iron).
Note that like for all components of the facility, each element of the mechanical structure will be monitored, identified and listed
in a database accessible to the collaboration. A sample will be systematically collected, radiopurity measured and archived.
Miscellaneous responsibilities
In parallel to scientific and technical tasks, the group is in charge of several community tools for the NEMO-3/SuperNEMO
collaboration:
• the management of 12 mailing lists for 120 collaborators,
• the hosting of the collaboration's private Wiki-based web site,
• the hosting of the Subversion server for official software development,
• the responsibility of the NEMO-3/SuperNEMO public web site,
• the responsibility of the computing resources at CCIN2P3 for the collaboration.
These tasks are carried out with the technical support of the LPC Caen IT service and the CCIN2P3. The group also
participates actively to the SuperNEMO Institutional Board (IB) and Technical Board (TB).
Fig. 14: On the left: geometry and discretization of the prototype within Maentouch software framework. On the right : Vertical component of magnetic field inside the prototype (lines: simulation for different iron magnetic permeability , red points: measurements).
52
References
[Bak06] C. A. Baker et al., Phys. Rev. Lett. 97, 131801 (2006).[Ban13] G. Ban et al., Ann. Phys. (Berlin) 525 (2013) 576.[Blie08] J. Blieck et al., Rev. Sci. Instrum. 79, 103102 (2008)[Bong13] M. Bongrand, Latest NEMO-3 results and status of SuperNEMO, TAUP 2013[Brei12] M. Breitenfeldt et al., IS433 experiment, CERN-INTC-2012-024.[Cour12] C. Couratin et al., Phys. Rev. Lett. 108 (2012) 243201.[Cour13] C. Couratin's thesis (2013).[Cour13b] C. Couratin et al., Phys. Rev. A 88 (2013) 041403.[CSIN2P3] SuperNEMO France, Searching for lepton number
violation with the SuperNEMO experiment , Proposal for the participation of France in the construction of a preproductionprototype (demonstrator module) of the SuperNEMO double beta decay detector , Conseil Scientifique de l'IN2P3 (2011)[Dorn00] R. Dörner et al., Phys. Rep. 330, 95 (2000)[Fabi] X. Fabian's thesis.[Knec13] A. Knecht et al., AIP Conf. Proc. 1560 (2013) 636.[Lerr12] A.Lerrede et al., PRA 85, 032710 (2012)[Lerr12b] A.Lerrede et al., PRL 111, 133201 (2013)[Lien12] E. Liénard et al., Proposal E646S, GANIL PAC October2012.[Pitc09] J.R.A. Pitcairn et al., Phys. Rev. C 79, 015501 (2009)[Sak67] A. Sakharov, JETP Letters, 5, 24-27 (1967).[Ujic12] P. Ujic et al., Proposal E658S, GANIL PAC October 2012.
Publications
High resolution probe of coherence in low-energy charge exchange collisions with oriented targetsLeredde A., Fléchard X., Cassimi A., Hennecart D., Pons B.Physical Review Letters 111 (2013) 133201
An endoscopic detector for ultracold neutronsGöltl L., Chowdhuri Z., Fertl M., Gray F., Henneck R. et al.European Physical Journal A: Hadrons and Nuclei 49 (2013) 9
Energy-dependent relative charge transfer cross sections of Cs+ + Rb(5s, 5p)Nguyen H., Brédy R., Fléchard X., DePaola B.D.Journal of Physics B 46 (2013) 115205
Precision measurements in nuclear β-decay with LPCTrapBan G., Durand D., Fléchard X., Liénard E., Naviliat-Cuncic O.Annalen der Physik 525 (2013) 576-587
Electron shakeoff following the Β+ decay of trapped 35Ar+ ionsCouratin C., Fabian X., Fabre B., Pons B., Fléchard X. et al.Physical Review A 88 (2013) 041403
Measurement of the transverse polarization of electrons emittedin free neutron decayKozela A., Ban G., Białek A., Bodek K., Gorel P. et al.Physical Review C 85 (2012) 045501
Atomic-matter-wave diffraction evidenced in low-energy Na++Rb charge-exchange collisionsLeredde A., Cassimi A., Fléchard X., Hennecart D., et al.Physical Review A 85 (2012) 032710
Undergraduate research opportunities in neutron activation analysis for local, regional and international studentsLandsberger S., Tipping T., Ezekoye O., Tamalis D., Lott V. et al.J. Radioanalytical Nuclear Chemistry 291 (2012) 59-61
First Measurement of Pure Electron Shakeoff in the β Decay of Trapped 6He+ IonsCouratin C., Velten P., Fléchard X., Liénard E., Ban G. et al.Physical Review Letters 108 (2012) 243201
Publications
High resolution probe of coherence in low-energy charge exchange collisions with oriented targetsLeredde A., Fléchard X., Cassimi A., Hennecart D., Pons B.Physical Review Letters 111 (2013) 133201
An endoscopic detector for ultracold neutronsGöltl L., Chowdhuri Z., Fertl M., Gray F., Henneck R. et al.European Physical Journal A: Hadrons and Nuclei 49 (2013) 9
Energy-dependent relative charge transfer cross sections of Cs+ + Rb(5s, 5p)Nguyen H., Brédy R., Fléchard X., DePaola B.D.Journal of Physics B 46 (2013) 115205
Precision measurements in nuclear β-decay with LPCTrapBan G., Durand D., Fléchard X., Liénard E., Naviliat-Cuncic O.Annalen der Physik 525 (2013) 576-587
Electron shakeoff following the Β+ decay of trapped 35Ar+ ionsCouratin C., Fabian X., Fabre B., Pons B., Fléchard X. et al.Physical Review A 88 (2013) 041403
Measurement of the transverse polarization of electrons emittedin free neutron decayKozela A., Ban G., Białek A., Bodek K., Gorel P. et al.Physical Review C 85 (2012) 045501
Atomic-matter-wave diffraction evidenced in low-energy Na++Rb charge-exchange collisionsLeredde A., Cassimi A., Fléchard X., Hennecart D., et al.Physical Review A 85 (2012) 032710
Undergraduate research opportunities in neutron activation analysis for local, regional and international studentsLandsberger S., Tipping T., Ezekoye O., Tamalis D., Lott V. et al.J. Radioanalytical Nuclear Chemistry 291 (2012) 59-61
First Measurement of Pure Electron Shakeoff in the β Decay of Trapped 6He+ IonsCouratin C., Velten P., Fléchard X., Liénard E., Ban G. et al.Physical Review Letters 108 (2012) 243201
53
Service administratif
Bureau d’études et mécanique
Service électronique et microélectronique
Service informatique
Service instrumentation
Documentation
Qualité et soutien aux projets
Hygiène et sécurité
ACTIVITÉSTECHNIQUES ET ADMINISTRATIVES
54
SERVICEADMINISTRATIF
ServiceAdministratif
Composé de trois agents CNRS et d’un agent
universitaire, le service administratif assure un rôled’interface avec les tutelles de l’unité (CNRS – IN2P3,ENSICAEN, UCBN) ainsi qu’un rôle d’assistance et deconseil auprès de l’ensemble des personnels du laboratoire.Le service traite tous les actes administratifs des domainessuivants :
La gestion des personnels Le service effectue le suivi de tous les agents de l’unité, ce qui se concrétise par divers actes administratifs (gestion des congés, gestion des compte-épargne temps, dossiers de carrière, avancement,etc…) ainsi que par la diffusion d’informations réglementaires.De plus, le pôle administratif se charge de l’accueil, de l’aideà l’installation des personnels non-permanents (13doctorants, 25 à 30 stagiaires tous niveaux et 7 visiteursétrangers par an) ainsi que de l’instruction et du suivi desgratifications de stage et des demandes de recrutement descontractuels rémunérés sur les ressources propres del’unité.
La gestion financière et la gestion des missionsLe service assure l’exécution du budget du laboratoire ainsique le suivi des crédits. Il traite dans le respect des règles envigueur une multitude d’actes administratifs se traduisant parl’engagement des dépenses (commandes, missions, achatscarte bleue), la validation des ordres de missions et desréservations de billetterie et d’hôtel, le calcul du montantdes remboursements dû aux agents, la transmission des étatsde frais au paiement, la liquidation des factures, la gestiondes immobilisations.Les crédits provenant du CNRS, de l’ANR et de l’Europesont gérés sous GESLAB ; les crédits provenant du MESR, dela Région Basse-Normandie (1 en cours) et des contratsindustriels (1 en cours), sont gérés sous SIFAC.
La gestion des relations internationalesLe LPC a plusieurs collaborations avec des organismes derecherche à l’étranger via les accords de coopération IN2P3(5 en 2012 et 3 en 2013), les programmes européens (2contrats en cours) et les contrats ANR (1).Le service aide au montage des projets et collaborations,assure le suivi et la justification des contrats en partenariatavec le Service Partenariat et Valorisation et la CelluleContrat de la Délégation Normandie. Enfin, il organise lesconférences, colloques, workshop en collaboration avec lesscientifiques.
Le secrétariatLe service apporte une aide à la saisie et à la mise en formede rapports, courriers, notes, en français ou en anglais.Il assure également des tâches plus générales commel’accueil téléphonique, le traitement et l’acheminement descourriers ainsi que l’approvisionnement en fournitures debureau et le transport des colis en collaboration avec laplateforme ULISSE.Il gère également l’annuaire du personnel, les badges d’accèsau site ainsi que les cartes de restauration.
Services généraux
Un agent CNRS est l’interface avec le Service TechniqueImmobilier de l’ENSICAEN.Il assure l’entretien, l’amélioration et l’aménagement deslocaux, la gestion et l’entretien du parc automobiles (2véhicules), la réception et la distribution des colis, les achatsde proximité avec la carte achat.Il est également chargé de la mise aux normes du réseauélectrique en collaboration avec une entreprise spécialisée etde la gestion des contrats de maintenance pour leséquipements de l’unité.
M. de Claverie (resp.), V. Devaux, A. Gontier, O. Guesnon, L. Lancien
55
BUREAU D’ÉTUDES ET MÉCANIQUE
B. Bougard, P. Desrues, H. Franck de Préaumont, D. Goupillière, J. Lory, Y. Merrer (resp.), C. Pain
Missions,Compétences,Moyens
Le service mécanique est en charge de l’étude, de laréalisation et de l’intégration sur site des parties mécaniquesdes instruments scientifiques développés par le laboratoire. Ilrépond également aux demandes faites dans le cadre desactivités d’enseignements dispensées à l’ENSI Caen et àl’Université de Caen Basse Normandie. Le service estcomposé d’un bureau d’études (4 personnes) et d’un atelierde fabrication (3 personnes).Le bureau d’études dispose de moyens IAO/CAO (Catia V5,SmarTeam, Ansys 14) lui permettant d’assurer la conception,les calculs et les dossiers de réalisation.L’atelier est doté de moyens de fabrication conventionnels etnumérisés ainsi que d’un logiciel de CFAO (Mastercam V6). Ilassure la réalisation et la mise au point des dispositifs conçusainsi que leur montage sur sites expérimentaux. Nos moyensnous permettent la réalisation d’ensembles de mécaniquegénérale et de chaudronnerie ainsi que le polissage et lenettoyage des pièces. L’atelier réalise la quasi-totalité despièces et ensembles conçus dans la limite des capacités denos machines.
Les compétences Étude et conception mécanique. Simulation mécanique et thermique. Ingénierie mécanique, dossier industriel, suivi deréalisation.
Fabrication mécanique et soudure. Montage, alignement et intégration sur site.
Les moyens La conception CAO - logiciel Catia V5 La gestion de données techniques - logicielSmarTeam
Le calcul par éléments finis - logiciel Ansys 14 La CFAO - logiciel Mastercam Un centre d’usinage à commande numérique. Un tour par apprentissage numérisé. Des machines outils conventionnelles et desmoyens de soudage
Des moyens de contrôles et de nettoyage.
Le laboratoire est impliqué dans des projets dans le cadre decollaborations nationales et internationales, le servicemécanique a en conséquence une bonne pratique du travailen mode projet et de la qualité.Les nombreux achats effectués tout au long de l’annéenécessitent la maîtrise des règles de consultations et d’achatsdes différentes tutelles. Enfin, l’utilisation régulière de la sous-traitance nous permet d’avoir une bonne connaissance dutissu industriel de notre domaine d’activité.
Réalisation, Montage et Alignement &
Conception Mécanique CAO Catia V5
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Projets et activités
SPIRAL2 Phase 1 – MONTAGE DES LIGNESACCÉLÉRATRICES
Au côté des équipes techniques du Ganil, montage et alignementdes lignes accélératrices de la phase 1 du projet Spiral2.
SPIRAL2 - Démonstrateur SHIRac2 (Refroidisseurquadrupôle à radiofréquence)
Développement d’un démonstrateur de refroidisseur de faisceaud’ions à gaz.Étude et réalisation de l’ensemble de la ligne sous vide et de seséquipements associés.
SPIRAL2 – RFQ-Cooler (Refroidisseur quadrupôle àradiofréquence pour Spiral 2)
Étude du refroidisseur quadrupôle à radiofréquence pour la phase2 du projet Spiral2. Cet ensemble répond aux exigences en termesde nucléarisation du projet (maintenance, maintien duconfinement, …).
SPIRAL2 – IBE (Station d’identification de faisceaux d’ionsradioactifs basse énergie)Étude d’une station d’identification de faisceaux radioactifs.Dispositif de détection composé d’un dérouleur de bande surlaquelle les ions sont implantés et de détecteurs permettant lamesure en 2 points grâce à des détecteurs Germanium, desdétecteurs Silicium et des scintillateurs solides.
SPIRAL2 – PTFI (Profileur Très Faible Intensité)Études et réalisation des parties mécaniques d’un démonstrateurde profileur de mesure de faisceau de très faible intensité pour leprojet Spiral2.
LIRAT - EMILIEDans le cadre d’une collaboration avec le Ganil, étude etréalisation d’un Debuncher destiné à être monté sur l’installationLirat au Ganil et sur le démonstrateur SHIRaC2 au LPC.
Etude et réalisation d’ensembles dans le cadre de collaborationsavec d’autres laboratoires.
Implantation et Alignement des châssis du LINAC
Alignement et Montage de la ligne LME
Modèle CAO de l’ensemble de la ligne
Ensemble du dispositif monté dans le hall du LPC
RFQ-Cooler
Modèle CAO du débuncher
Ensemble réalisé au LPC
Réalisation d’un piège à Ions pourl’université King Khalid (Arabie Saoudite)
Détecteur Ion de recul pour l’Argonne National Laboratory (USA)
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SUPER NEMOPour la collaboration internationale, étude de la bobine dudémonstrateur de SuperNemo qui sera installé au LaboratoireSouterrain de Modane. Etude et réalisation d’un prototype debobine permettant de caractériser et de valider les dimensionsde la bobine du futur démonstrateur.
nEDM (Le moment dipolaire électrique du neutron)Développement de dispositifs pour l’installation nEDM à l’InstitutPaul Sherrer (PSI) en Suisse.Étude et réalisation mécanique d’ensembles de détection ainsique de dispositifs de mesure associés.
ARCHADE – REC HADRONPour le futur centre de recherche en hadronthérapie Archade,dans le cadre du projet Rec Hadron étude d’une chambre à videmodulaire et de ses équipements associés (porte-cibles, plateaumobile, groupe de pompage …)
FRAGMENTATIONEtude et installation de dispositifs expérimentaux au Ganil.
DOSIONRéalisation de chambres à ionisation et intégration sur une ligneexpérimentale au Ganil.
FALSTAFF
Etude, réalisation et montage d’ensembles de détection destinés àmesurer les fragments de fissions induites par des neutrons dansle cadre du projet NFS. Travail réalisé en partenariat avec l’IRFUet monté sur leurs installations à Saclay.
FAZIA (Multi détecteur 4=)
Dans le cadre de la collaboration internationale, participation auxétudes du bloc de détection composé de détecteurs Silicium etde CsI.Etude de l’assemblage de 12 blocs suivant différentesconfigurations et étude de leur intégration au sein d’Indra.Réalisation d’un prototype de support de bloc pour lesexpérimentations en cours.
Bilan
Le service mécanique est engagé dans de nombreuses études etréalisations. La diversité des projets retenus par le laboratoirenécessite de la part des membres du service une adaptabilité detous les jours.
Les collaborations sont nombreuses et de plus en plus orientéesà l’internationale. L’utilisation d’outils de gestions de donnéestechniques, de conduites de projets et d’assurance qualité tend àse généraliser à tous les projets. Les fréquentes collaborationsinternationales nécessitent l’usage de l’anglais pour les membresdu bureau d’études et ceux de l’atelier assurant les intégrationssur sites.
Le service est très sollicité, son équipe et son organisation luipermettent de répondre aux multiples demandes des équipes derecherche du laboratoire.
Modèle CAO de la Bobine du démonstrateur de SuperNemo
MAPPER : Dispositif amagnétique de
cartographie automatisé du champ magnétique
à l’intérieur de l’enceinte
FRACAS : Modèle CAO de l’ensemble de la chambre à vide en Inox (Ø2m Lg 7m)
Détecteur Scintillateur réalisé au LPC
Détecteur IC Dosion 3
Modèle CAO de l’ensemble de détection Dispositif monté à l’IRFU à Saclay (juin 2013)
Modèle CAO du dispositif de Mesure de résolution
Intégration d’un ensemble de 12 blocs à l’intérieur de l’enceinte Indra suivant une configuration « mur ».
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SERVICE ELECTRONIQUE ET MICROÉLECTRONIQUE
F. Boumard, J.-F. Cam, S. Drouet, L. Fédor*, P. Laborie (resp.), J. Langlois, A. Leconte, L. Leterrier.
Missions et Compétences
Notre mission principale est de répondre aux besoins
des expériences et projets de physique en concevant et enréalisant des systèmes dans les domaines de lamicroélectronique, l’électronique analogique, l’électroniquede puissance et les radiofréquences. Cela implique de menerune veille technologique permanente, de construire desdémonstrateurs et prototypes, d’effectuer des tests.Nous avons une forte activité en R&D de manière à pouvoirrapidement nous adapter aux demandes à venir de laphysique.Durant les deux dernières années, l’activité du service a étéprincipalement marquée par une implication forte dans deuxprojets majeurs : SPIRAL2 et SuperNEMO ; la croissance dela demande des physiciens en matière de RFQ coolers ;l’avancée de notre R&D en préamplificateurs de charge, quis’est traduite par des applications et de nouvellescollaborations.Les paragraphes suivants donnent un aperçu de nos diversesactivités.
Activités liées à SPIRAL2
Le RFQ cooler
Les travaux sur le RFQ cooler se partagent en deux projets :Le projet SHIRaC qui consiste à développer au laboratoireun démonstrateur permettant de valider les spécificationstechniques du RFQ cooler conçu dans le projet RFQCooler de SPIRAL2. La construction du RFQ CoolerSHIRaC s’est terminée fin 2010. De nombreuses campagnesde mesure ont été effectuées pour qualifier l’instrument :mesures de transmissions, d’émittances et de dispersions enénergie avec des faisceaux de différentes natures (en intensitéet masse). Le démonstrateur a été travaillé pour améliorer safiabilité et ses performances en termes de manipulation defaisceau. La précision requise pour les mesures de dispersion
en énergie des ions à la sortie du RFQ cooler a nécessité unlong et délicat travail sur la conception et la validation de 2détecteurs spécifiques. Les performances obtenues durantl’année 2013 répondent aux exigences du cahier des chargesen termes de transmission (>50 %) et d’émittance(≤3 Q·mm·mrad). Concernant la dispersion en énergie(≤1 eV), les résultats se rapprochent très fortement de lavaleur requise.
Performances obtenues :
* Contrat temporaire d’avril 2012 à août 2013.
Le démonstrateur SHIRaC au LPC CAEN
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Intensité faisceau (nA) Transmission (%) Emittance transverse (6·mm·mrad)
Dispersion en énergie lognitudinale (eV)
50 74,2 2,1 0,8500 76,2 2,2 1,21000 76,4 2,2 1,3
Résultats des mesures d’émittance et de dispersion en énergie
Concernant le projet RFQ cooler de SPIRAL2 – Phase2, lestravaux de conception du RFQ cooler adapté à l’architecture dubâtiment de production de faisceaux radioactifs ont permis derédiger la première version dossier de définition. L’étatd’avancement de la conception de l’instrument a été présentélors d’une revue de définition organisée par l’équipe de directiondu projet SPIRAL2.
Les PTFI (Profileurs Très Faible Intensité)Un prototype d’amplificateur d’instrumentation à fort gain(46 dB), large bande (50 MHz) et faible bruit (3 mV rms) a étéréalisé en 2013 afin de traiter les signaux différentiels faiblesniveaux (qq 100 µV) issus d’un PTFI. Les tests de ce prototypeavec un détecteur étant satisfaisants, la réalisation d’une carte auformat µTCA incluant 5 voies amplificatrices a été lancée fin2013 et devrait être testée début 2014.
Le contrôle projet SPIRAL2Comme présenté dans ce rapport d’activité, le laboratoire estimpliqué dans plusieurs tâches concernant SPIRAL2, futureinstallation qui va étendre les capacités du GANIL en termes defaisceaux exotiques. Dans ce cadre, un ingénieur du service estcontrôleur projet depuis 2006. Il est en charge du planningdirecteur du projet, de l’organigramme des tâches et de lagestion des risques projet. Il est membre de la direction de ceprojet. Carte µTCA amplificatrice 5 voies
Prototype de l’amplificateur
Maquette 3D du RFQ cooler au LPC CAEN
Activités pour SuperNEMO
Le circuit intégré FEAST (Front-End ASIC for SuperNEMO Tracker) a été conçu pour répondre aux exigences du systèmede tracking de SuperNEMO. Ce circuit intègre une électronique permettant de traiter jusqu’à 54 voies. FEAST fournit unemesure de temps sur les signaux provenant des chambres à dérive avec un pas et une résolution inférieure à 15 ns.Cet ASIC a été conçu, routé et fabriqué en 2011.En 2012, 20 puces encapsulées ont été testées au LPC sur un banc de test générique qui nous a permis de valider les différentescaractéristiques comme par exemple : la résolution temporelle =3.62 ns rms, la non-linéarité différentielle=369 ps, la non-linéarité intégrale =806 ps. A la suite de ces bons résultats, des tests sur 18 prototypes de cellules fonctionnant en régimeGeiger ont été réalisés à Manchester (Royaume-Uni). Seuls les signaux anodiques ont pu être traités, les signaux cathodiquesn’étant pas câblés au niveau des détecteurs.Ces tests nous ont permis de :valider les fonctionnalités et les performances de FEAST monté sur des détecteurs Geiger avec des signaux anodiques,nous apercevoir que notre banc de test générique avait des problèmes de transmission de données.Courant 2013, un banc de test spécifique a été développé pour remplacer le précédent sur la base d’une architecture plussimple. L’interface utilisée est une interface USB et les premiers tests réalisés nous montrent que les transmissions s’effectuentcorrectement quelque soit le flot de données.
Aux vues des bonnes performances de FEAST, une série de 150 ASICs a été produite dans le but d’équiper les cartes Front-End Board développées par nos collègues de Manchester et contribuant ainsi à la construction du prototype de SuperNEMO.Ces 150 ASICs seront testés et validés par un banc de test automatique dont la conception a débuté fin 2013.
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Activités liées aux projets Emilie etPiperade
Le projet PIPERADE (PIège de PEnning pour des ionsRAdioactifs à DEsir) est piloté par le CENBG (Centre d’EtudesNucléaires de Bordeaux Gradignan). Celui-ci inclut un RFQcooler buncher pour lequel il nous a été demandé d’apporternotre expertise dans la conception du système de production destensions Radio-Fréquences de l’instrument.
Le projet EMILIE (Enhanced Multi-Ionization of short-LivedIsotopes at Eurisol) consiste entre autres à concevoir etexpérimenter un RFQ debuncher. Notre mission est deconcevoir et construire d’une part le système de production des2 tensions radiofréquences nécessaires à la production du champde confinement du quadripôle et d’autre part développer legénérateur des tensions impulsionnelles appliquées aux 23segments. La solution retenue pour générer les tensions desegments est composée de 2 générateurs arbitraires multivoiesdont les signaux sont adaptés en amplitudes par 8 amplificateursmodulaires, les 8 tensions produites sont distribuées sur les 23segments. Ce dispositif permet de produire les cycles depiégeages et d’expulsion des ions stockés au centre duquadripôle. Le système de production des tensions RF est basésur un circuit résonnant utilisant un condensateur variable hautetension et deux bobines à air, le couplage du circuit résonnant àl’amplificateur de puissance est assuré par une boucle d’induction.
Banc de test générique ASICs FEAST (boitier et puces nues)
Production de 150 ASICspour construction prototype SNEMO
Banc de test spécifique USB
Banc de test RF du debuncher
Le choix des équipements nécessaires à la production des tensions de piégeages a été effectué, le circuit de distribution destensions a été finalisé est pourra être implanté sur le RFQ debuncher. L’instrument et ses équipements électroniques serontimplantés sur le banc de test du démonstrateur du RFQ cooler de SPIRAL2. Les premiers tests devraient être effectués endébut d’année 2014.
Activités pour DOSION
La carte CARAMEL (CARte d’Acquisition Multivoies Electromètres) est une carte d’acquisition de faibles courants
disposant de trois calibres : 3 pC, 6 pC et 12 pC. Elle peut intégrer des charges sur 12 bits à 10 µs ou 16 bits à 20 µs sur 16voies simultanément.La gamme d’entrée en acquisition de charge s’étend de -1.786 % de la valeur positive max de la plage de mesure (3, 6 ou12 pC) à 3, 6 ou 12 pC selon le calibre.Elle dispose :de 32 entrées via un connecteur SAMTEC ERI8d’un connecteur Vita 57 LPC. La carte électromètre est une carte fille qui se connecte sur une carte mère FASTER. La cartemère fournira les alimentations, les horloges à la carte CARAMEL. La carte fille retournera à la carte mère les signauxnumérisés.
Vue de la carte CARAMEL
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Son implication dans DOSION avec un système constitué dedeux cartes CARAMEL permet de pouvoir localiser le faisceau enX sur 32 voies, en Y sur 32 voies et aussi de quantifier l’énergiecollectée sur chaque voie X ou Y.
R&D et contributions à la R&D dulaboratoire
R&D en préamplificateurs de charge intégrésAprès une période d'étude et de conception, un ASIC a étésoumis à la fonderie en janvier 2011. Cet ASIC est composé de 7PAC (PréAmplificateurs de Charge) différents. Ces septconfigurations nous ont permis de comparer les différentesstructures en matière de performance. Les différences entre ces7 PAC sont la résistance de contre-réaction (active ou passive),la polarité (unipolaire ou bipolaire), le gain (fixe ou configurable),et la connexion de substrat (commune avec la masse ouindépendante). Les tests faits en 2012 sur cet ASIC ont donnélieu à un rapport détaillé permettant la comparaison entre lesdifférentes architectures en matière de bruit, linéarité,dynamique, charge équivalent de bruit, etc…
Deux PAC ressortent de toutes ces comparaisons.Le premier est un PAC dont la polarité peut être choisie (soitunipolaire, soit bipolaire) et ayant une capacité de contre-réaction de 1 pF. Ses principales caractéristiques : bruit largebande=265 µV (unipol.) et 545 µV (bipol.), linéarité de ±1 % surune dynamique de 1,8 pC, un CEB min=549 e- (unipol.) et 863 e-
(bipol.).
Le deuxième est un PAC dont la polarité peut être choisie (soitunipolaire, soit bipolaire), et ayant des capacités de contre-réaction programmables de 0 à 15 pF par pas de 1 pF. Sesprincipales caractéristiques : bruit large bande=350 µV (unipol.)et 564 µV (bipol.), linéarité de ±0,7 % sur une dynamique de1,7 pC (pour Cf=1 pF), un CEB min=841 e- (unipol.) et 1200 e-
(bipol.).
Un test avec détecteur silicium a aussi été réalisé sur le premier PAC, ce qui nous a permis de mesurer sa résolution qui est de24 keV LTMH avec une source tri-alpha et un shaping time de 0,5 µs.Dans la continuité de ce travail de R&D et en collaboration avec un collègue microélectronicien du GANIL, nous avonsdéveloppé en 2013 un ASIC préamplificateur de charge configurable nommé C2SA pour Configurable Charge Sensitive Amplifier.Celui-ci a été conçu pour répondre aux besoins de la plupart des expériences de physique nucléaire. Les spécifications de cePAC sont les suivantes :
Gamme en énergie jusqu’à 1,5 GeV, Taux de comptage < 250 kHz, Polarité des signaux d’entrée unipolaire ou bipolaire, Temps de montée des signaux d’entrée >10 ns, Résolution de 10 keV Silicium à 5,5 MeV, Linéarité <1 %, Capacité d’intégration sélectionnable de 1 pF à 42 pF, Résistance de contre-réaction sélectionnable de 280 kΩ à 5 MΩ.
En plus de la fonction pré-amplification de charge, cet ASIC intègre : Un esclave I²C réalisé par l’IPN Lyon pour le slow control, Une interface de secours en doublon de l’esclave I²C, Un générateur d’impulsions pour les tests/calibration (Amplitude réglable sur 10 bits), Un discriminateur à seuil sortant au standard LVDS (Seuil réglable sur 10 bits).
La caractérisation de cette ASIC sera réalisée début 2014.
Carte de test de l’ASIC C2SA
Layout de l’ASIC C2SA
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R&D en préamplificateurs de charge discretsAfin d’étendre l’offre sur l’électronique frontale discrète du SEM,une R&D sur des PAC avec sortie temps a été menée en 2013.La particularité de ces PAC est d’offrir, en plus du signal decharge, un signal impulsionnel très rapide homothétique enamplitude et minimisé en « walk » sur la gamme defonctionnement. Le « walk » étant le déplacement temporel enfonction de la variation d’amplitude du signal d’entrée, il doitdonc être minimisé afin de ne pas dégrader la mesure de tempsde vol.Les principales caractéristiques de la version la plus performantesont :Sortie Charge : Bipolaire ; Plage de sortie≈±2,6 V ; INL≈±0,6 % ;CEBmin≈570 e- pour Cf=2,6 pF et Rf=10 MΩ.Sortie temps : Signal impulsionnel négatif ; Temps de montée<2 ns ; Amplitude minimum≈-52 mV ; Walk≈140 ps pour unedynamique d’environ 30 ; Walk≈60 ps pour une dynamiqued’environ 10. (Ces résultats sont donnés pour Cf=1 pF).Afin de finaliser la caractérisation de ces PAC, des mesures avecun détecteur seront effectuées en 2014.
R&D sur la mesure de tempsBloc 50 ps :L’équipe microélecronique du SEM, engagée dans la R&D sur lamesure du temps, a conçu fin 2009 un ASIC interpolateur detemps à 50 ps de pas quantification. Cet interpolateur met enœuvre une structure asservie innovante qui devrait permettred’atteindre une résolution temporelle d’environ 30 ps.A cause de projets plus prioritaires, la caractérisation de cetASIC a dû être mise en attente. En 2013, un banc de test a étéréalisé et les premiers résultats sont très encourageants(DNL<±16 ps ; INL<±85 ps et Résolution <25 ps rms). Les testsseront finalisés en 2014.
SCATS :SCATS (Sixteen Channel Absolute Time Stamper) est un ASICmarqueur de temps haute résolution, grande dynamique et fortdébit réalisé en collaboration avec le LAL d’Orsay pourl’expérience SuperB. Cet ASIC comporte 16 voies de mesures detemps indépendantes permettant la mesure du temps de vol desparticules ainsi que le marquage en temps des événements à destaux de comptage élevés (qq MHz/voie).Cet ASIC a été caractérisé en 2012 et les performances obtenuessont : DNL < ±40 ps, INL < ±110 ps et Résolution < 86 ps rms.En prenant en compte la courbe d’INL, la résolution maximale aété diminuée à 65 ps rms.Dans un premier temps, SCATS a été encapsulé sous un boitierCQFP 120 au pas de 0,8 mm et afin d’augmenter l’intégration, leboitier est a été remplacé par un CQFP 128 au pas de 0,4 mm.
Contribution à la R&D sur les détecteurs diamantsEn vue d’utiliser des détecteurs diamant segmentés double facepour la localisation spatiale de particules (diagnostic faisceau), leSEM a réalisé en 2013 une carte ETC (Eight Time Channels) auformat VITAL57. Cette carte comporte 8 voies de mesure detemps/énergie réalisées à partir de deux ASICs : L’ASIC NINOqui est un amplificateur/discriminateur multivoies conçu auCERN et l’ASIC SCATS qui est un marqueur de temps hauterésolution multivoies conçu par le LPC Caen et le LAL.
-25
-20
-15
-10
-5
0
5
10
15
20
25
0 20 40 60 80 100 120
DNL voie 2 en ps
DNL corrigée
DNL DLL0
DNL DLL1
PAC avec sortie temps
Carte de test de l’ASIC Block_50 psDNL d’une voie en ps
Résolution temporelle
Layout de SCATSCarte de test et boitiers de SCATS
Résolution temporelleentre 2 voies de mesure
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Cette carte devra respecter les spécifications suivantes : Gamme des signaux d’entrée de 30 fC à 16 pC, Signaux d’entrée impulsionnels très rapides (temps demontée ~1 ns, durée ~6 ns)
Taux de comptage total <1 MHz, Résolution temporelle <200 ps rms, Temps mort individuel d’une voie <100 ns.
La carte ETC sera connectée à la carte SYROCO du systèmeFASTER développé par le service instrumentation du LPC Caen.La caractérisation de la carte ETC sera faite en 2014.
ConceptionAssistée par Ordinateur
Notre institut (IN2P3) est structuré de manière à avoir
une personne en charge du suivi des outils CAO (ConceptionAssistée par Ordinateur) dans chaque laboratoire. Lecorrespondant CAO du LPC Caen est une personne du service.Au laboratoire, nous utilisons différents outils de conceptionassistée par ordinateur pour répondre aux différents besoins dulaboratoire et plus généralement de l'institut.Nous disposons de plates-formes logicielles via l’IN2P3 :simulation, saisie schématique et routage (CADENCE) pourl’électronique et la microélectronique.En ce qui concerne l'électronique numérique, nous avons accès àdifférents outils de synthèse logique (Synopsys, Quartus, ModelSim). Nous utilisons également des licences Altium Designerinstallées en interne pour nos développements commerciaux.
Ci-après quelques exemples de réalisations du laboratoire.
Carte ETC pour détecteur diamant
Synoptique de la carte ETC
IGBT 1
0,7H
Bobine
0,7H
Bobine
Diode HT
70 Volts
GENE. U
50nF/10KV7000 Volts
GENE. U HT
I
IGBT 2
Commutateur HT
2A / 10KV
à MOSFET
TVS
TVS
30 x 40 Volts
Circuit d'absorption de
l'énergie stockée dans les
bobines400 Volts
1200 Volts
=
Exemples de réalisations obtenues avec les logiciels de CAO du laboratoire
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Formations et réseaux
Plusieurs agents du service donnent des cours à nos collègues de l’IN2P3 et du CNRS, ainsi qu’aux étudiants.
Ainsi, nous sommes impliqués dans plusieurs écoles IN2P3 : techniques de base des détecteurs, microélectronique, conduite deprojet.
Nous intervenons aussi dans deux mastères professionnels : « SNEAM : Sustainable Nuclear Engineering – Applications and Management » à l’ENSICAEN et « Instrumentation Nucléaire » à l’Université Bordeaux 1.
De plus, nous sommes impliqués dans plusieurs réseaux métiers de l’IN2P3 : CAO (Conception Assistée par Ordinateur),formation, valorisation, qualité, réseau des responsables techniques de l’IN2P3.
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SERVICE INFORMATIQUE
Le service a trois principales missions : la gestion des ressources informatiques du laboratoire, le support et la conception des développements logicielsspécifiques pour les expériences de physique,
la diffusion de l’information scientifique et technique.
Mouvement de personnel
Yoann Kermorvant a été recruté sur un poste de techniciensuite à un concours externe. Il a pris ses fonctions enoctobre 2012 et fait partie de l’équipe qui gère lesressources informatiques.
Gestion des ressources informatiques
Quatre personnes (2IE, 2T) assurent le fonctionnement,
la maintenance et l’évolution des infrastructuresinformatiques du laboratoire : l’administration et la maintenance des serveurs dedonnées sur stockage NAS,
l’administration et la maintenance des serveurs de calcul, l’administration et la maintenance des serveurs centrauxsous Windows Server (Active Directory) et Linux(Scientific Linux, CentOS et Ubuntu),
la maintenance, la configuration et les évolutions duréseau local et des accès à distance,
la définition, la mise en place et le contrôle des règles dela sécurité informatique,
les installations et les mises à jour automatiques despostes de travail sous Windows et Linux Ubuntu,
les installations et les mises à jour de tous les logiciels dedéveloppement, de calcul, d’analyse de données, de CAOélectronique (CADENCE, Altium, Quartus, SeeElectrical,…), mécanique (CATIA ; Mastercam) et debureautique,
la gestion des sauvegardes,
l’administration des serveurs de courrier, web et diversservices réseau (dns, ldap, dhcp, radius, firewall, etc…),
le suivi des problèmes et l’assistance aux utilisateurs, le système de visioconférence, la gestion de toutes les commandes informatiques dulaboratoire (matériels et logiciels).
Principales évolutions
- HelpdeskLe support aux utilisateurs a été revu. La documentation enligne a été entièrement réécrite et complétée. Un systèmede suivi de problème et d’assistance par tickets a été mis enplace. Il permet de mieux gérer les problèmes et surtoutleur suivi.Nous disposons aussi d’un wiki propre au service quicontient les documentations nécessaires à l’exploitation.
- SyslogLe système de log des serveurs (syslog) a été revu etcentralisé. Les traces sont conservées 1 an conformémentau décret relatif à la conservation des données descommunications électroniques.
- Nouveau serveur de fichiersUn nouveau serveur de ficher (DELL NX3500 / 36 To) a étémis en service afin d’offrir un volume de stockage plusimportant et d’améliorer les performances. Devant lesdemandes de stockage toujours plus importantes il faudracertainement envisager une extension volumétrique de ceserveur.
- Virtualisation5 serveurs Windows Server (4 2012 et 1 2008R2) sontdédiés à la virtualisation sous HyperV. On comptemaintenant une vingtaine de serveurs virtuels (Linux etWindows) en exploitation.
T. Chaventré, S. Guesnon, J. Hommet, Y. Kermorvant, T. Launay (Resp.), L. Noblet, J. Poincheval, D. Zwolinski
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- Courrier électroniqueNous avons migré notre serveur cyrus-imap/postfix versZimbra. Les utilisateurs ont accès maintenant à une interfaceunique conviviale et des outils collaboratifs dont le calendrierpartagé.
- CalculLa demande en moyen de calcul augmente régulièrement et sediversifie. Une ferme de calcul composée de 5 serveurs (120cœurs) est dédiée à l’exécution en mode parallèle des codesmcnp et mcnpx. Elle est utilisée à 100%. Nous avons déployéaussi un serveur doté de cartes NVidia Telsa pour l’utilisationdu code CUDA sur Gpu (896 cœurs). D’autres serveurs sontutilisés pour les calculs plus classiques. Le système de gestiondes batchs utilisé est « torque ».
- Gestion du parcNous utilisons maintenant GLPI et FusionInventory pour lagestion du parc. Les postes Ubuntu ont été migrés en version12.04 TLS. Ils sont installés et mis à jour automatiquement àl’aide du logiciel libre « m23 ». Les postes Windows sont tousen version Windows 7 (sauf exception) et déployés et mis àjour via MDT2012. Tous les disques des portables sontmaintenant chiffrés via le logiciel TrueCrypt
- RéseauLes VLAN’s ont été redéfinis et sécurisés. Un accès VPN via leservice « vpn reconnect » de Microsoft pour les postesWindows a été mis en service. Il est accessible uniquementaux portables du laboratoire gérés par le service informatique.
- WWWEn plus du serveur de projets Trac (23 projets recensés), 4serveurs WWW (Fazia, Hadronthérapie, Site ROOT enfrançais et Faster) dédiés aux projets et groupe de physiquesont hébergés sur nos serveurs ainsi que le site nornamDEV(Réseau régional DEVLOG (Réseau du DEVeloppementLOGiciel)) créé récemment.
- PSSIUn groupe d’étude a été constitué afin d’établir le documentdécrivant la politique de sécurité des systèmes d'informationdu laboratoire.
Développements d’applications
Trois ingénieurs (1IR, 2IE) assurent les développements
logiciels spécifiques pour les expériences de physique. Enparticulier pour le système d’acquisition FASTER et lesinterfaces graphiques associés qui sont maintenant mis àdisposition de la communauté scientifique.
FASTER
Faster est le plus important projet technique du laboratoire,alliant instrumentation, électronique et informatique. C'est lesystème d'acquisition du LPC, en service également dans denombreux autres sites. Faster un système d'acquisitionnumérique dont chaque donnée est datée individuellement. Lesystème, entièrement générique, vise les petites et moyennesexpériences, sans aucun à priori sur leurs natures. Issu duservice instrumentation, ce projet est basé sur une
distribution de FPGAs (composants électroniquesprogrammables) qui assurent le traitement numérique dessignaux de mesures, le codage des données, leur transport etleur filtrage.
La contribution du service informatique sur ce projet portenon seulement sur les parties logicielles classiques (IHM,commande/contrôle, stockage), mais aussi sur l'architectureincluant les FPGAs. En effet, nous avons conçu le "Modèled'Arbre d'Acquisition Synchronisé" sur lequel est baséel'architecture du projet. Cette architecture rend le systèmed'acquisition générique dans sa globalité : les décisionsopérées sur les données sont distribuées au plus près de leurssources, à l'inverse des systèmes classiques contraints par unelogique de décision fixée. Ceci procure des fonctionnalitésinédites aux systèmes d'acquisitions à tous les niveaux :maintenances, réglages, évolutions et développements.
L'infrastructure logicielle est écrite en Ada et les interfacesutilisateurs en Python. Ainsi, le cœur du système bénéficied'une technologie de pointe sur les fortes contraintes(robustesse, temps réel, concurrence, distribution), et resteextrêmement flexible en utilisation (IHM, scripts).Le projet, jalonné par les expériences du laboratoire,augmente en fonctionnalités et en composants à chaque étape.Sa conception modulaire simplifie son évolution.
RHB - ROOT Histogram Builder
ROOT Histogram Builder est un logiciel développé aulaboratoire et qui repose sur les librairies ROOT du CERNimplémentées en langage C++. Il est développé et maintenupar le service et est dédié à l'analyse et la visualisation dedonnées. RHB est utilisé pour les tests de détecteurs et lapréparation d'expériences au laboratoire. Il est aussi proposéà tous les utilisateurs de FASTER comme outilcomplémentaire aux ensembles FASTER distribués àl'extérieur, notamment pour l'analyse en ligne des données.RHB reste toutefois ouvert et extensible: il est par exemplecompatible avec d'autres systèmes d'acquisition comme leDAQ GANIL ou le système GANDALF, développé par leLaboratoire de Physique Subatomique et de Cosmologie deGrenoble (LPSC) et mis en œuvre pour le projet GUINEVERE(Generator of Uninterrupted Intense NEutrons at the leadVEnus Reactor) à Mol en Belgique.RHB suit les évolutions de FASTER notamment en termes demodules électroniques de mesure comme les derniersElectromètre et Scaler. En parallèle, RHB s'améliore enproposant ses propres évolutions. De nouveaux typesd'histogrammes et de paramètres ont ainsi vu le jour et unoutil de visualisation a été ajouté : l'option RHV (ROOTHistogram Visualizer), qui permet à l’utilisateur de créer et degérer son propre affichage de données dans une fenêtregraphique dédiée à base d'onglets.
En outre, afin d'améliorer le suivi et la production du logiciel,un serveur d'intégration continue Jenkins a été déployé. Destests sont aussi en cours pour intégrer l'outil Sonar, quidevrait permettre de mieux mesurer la qualité du codeproduit.
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Enfin, les développements actuels et à venir portent sur lagestion de familles de paramètres et d'histogrammes, et unenouvelle interface graphique de contrôle/commande est encours de réalisation.
Dépôt logiciel – distribution
Les deux projets RHB et Faster sont distribués sous forme depaquets Debian sur un dépôt hébergé au laboratoire. Cecipermet une installation intégrée aux systèmes Debian etUbuntu ainsi qu'une gestion transparente des mises à jourcoté utilisateur.
De plus, la documentation est rendue disponible sur le sitecommun « http://faster.in2p3.fr ».Voici la liste actuelle des utilisateurs de RHB et Faster :
Caen : LPC, GANIL, CIMAP, ENSI Caen, Université de CAEN,France : ILL (Grenoble), IPHC (Strasbourg), CEA (Bruyères etSaclay), Université d'Orsay,Suisse : CERN (Genève), PSI (Villigen),Espagne : Université de Muelva,USA : MSU (Michigan), CENPA (Seattle),Belgique : KUL (Leuven),Russie : JINR (Dubna).
normanDEV – Réseau des développeurs de Normandie
Un de nos ingénieurs, Thierry Chaventré, a créé et anime leréseau « normanDEV », le réseau des développeurs deNormandie. Ce réseau est affilié au réseau national DEVLOG(DEVeloppement LOGiciel inter-établissements CNRS, INRA,INRIA).
L'objectif principal de normanDEV est de réunir toutes lespersonnes ayant une activité de développement et dedéploiement du logiciel au sein d’établissementsd’Enseignement Supérieur et de Recherche en Normandie(ITAs, chercheurs, enseignants, doctorants).
Le but du réseau est d’une part d’échanger autour des
techniques, des bonnes pratiques, des outils et des méthodespour favoriser la veille technologique et la communicationentre entités, et d’autre part, d’échanger et de partager lesretours d’expériences sur le développement et la gestion deprojets logiciels.
Dans cette optique, Thierry Chaventré a créé des listes dediffusion, constitué un Comité de Pilotage et développé le siteweb http://normandev.cnrs.fr hébergé au laboratoire. Ilorganise tous les ans une manifestation autour dudéveloppement logiciel. L'agilité est le thème de la journée2014 constituée de deux ateliers Légo4SCRUM et CodingDojo.
Diffusion de l’information scientifique - Documentation -Web
Sandrine Guesnon, la documentaliste du laboratoire, estmembre du service informatique.
Au laboratoire :Elle assure la gestion des ressources documentaires,l'archivage en libre accès et l'exploitation des données de larecherche ainsi que la diffusion de l’information scientifique ettechnique.Elle prend part également à la gestion de la communication(interne, externe) en pilotant la cellule COM du laboratoireet en assurant l'actualisation du site Internet du laboratoire.
A l’IN2P3 :Elle est responsable du réseau Démocrite de l’IN2P3(bibliothèques et documentalistes de l'institut) etadministrateur du portail de ressources documentaires enIST de l’institut (http://documentalistes.in2p3.fr)
(Consulter la section « documentation » du rapport d’activitépour obtenir des informations complètes)
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SERVICE INSTRUMENTATION
Les missions du service instrumentation sont
essentiellement l’assistance aux équipes de recherche dulaboratoire et la recherche et développement technique dansses domaines de compétence.
Le domaine d’intervention du service est large, il intègreprincipalement les compétences suivantes : La conception et la mise en œuvre des détecteurs departicules.
Le développement d’acquisitions numériques spécifiquesà la physique nucléaire.
Le contrôle et commande des dispositifs expérimentaux. La maîtrise des techniques du vide. Les mesures de radioactivité.
Le service participe aux tâches collectives, une Personne estCompétente en Radioprotection (PCR), une autre estchargée de la sécurité (AP : Assistant de Prévention).
Les équipements et outils spécifiques à disposition du servicesont : Logiciels de CAO électrique, électronique. Logiciels de développement de programme et de FPGA. Une salle propre équipée pour la fabrication et lapréparation des détecteurs.
Un évaporateur pour la fabrication et l’intégration desdétecteurs.
Au cours de la période d’activité de référence, les deuxtemps forts au sein du service instrumentation ont été ledépart du service d’un ingénieur de recherche en septembre2012 et d’un adjoint technique en juin 2013 ainsi que lamontée en puissance du projet FASTER, acquisition dedonnées numériques, due à l’accélération du déploiement enEurope et aux Etats-Unis.
Détecteurs
Le service instrumentation dispose de compétencesdans le développement de détecteurs gazeux, scintillants ousolides utilisés dans le domaine de la physique nucléaire.En ce qui concerne les scintillateurs, ceux-ci sontgénéralement achetés à façon et assemblés aux tubesphotomultiplicateurs au sein du laboratoire. Les étudesportent généralement sur l’optimisation du couplage (via ounon un guide de lumière) et l’adaptation du photodétecteurau besoin précis exprimé pour l’expérience.De même pour les éléments de détections tels que les GEM(Gaz Electron Multiplier) ou les galettes à micro-canaux(MCP) achetées dans le commerce, puis associées à diversesélectrodes développées dans le laboratoire afin de répondreaux exigences de l’expérience.Par exemple, le profileur très faible intensité (PTFI) pourSpiral2 est constitué d’une MCP double étage et d’une anodede localisation résistive X/Y en circuit imprimé flexible enKapton® déterminant la position et la taille faisceau.
J. Bregeault, B. Carniol, D. Etasse, J-M. Fontbonne*, C. Fontbonne, J-L. Gabriel, J. Harang, J. Perronel, H. Plard*, C. Vandamme
* 2 personnes ont quitté le service en 2012 et 2013
Fig 1 : Vue éclatée du PTFI
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Fig 2 : Face arrière (anode) avec plage d’accueil des résistances / Zoom face avant Flex
Les détecteurs gazeux, en revanche, sont intégralementdéveloppés et réalisés par le service d’instrumentation. Nousdisposons d’un évaporateur équipé d’un canon à électron, quipermet de mettre en œuvre les techniques complexes demasquage utilisées pour le design d’électrodes particulières dechambres d’ionisation strippées ou à pads, ou bien dedégradeurs de champ pour les chambres à dérive, parexemple. Les circuits imprimés (Epoxy ou Kapton) dessinésavec le logiciel de CAO Altium Designer assurent le maintienmécanique et la gestion des signaux des éléments de mesures.
Les détecteurs solides (type silicium ou germanium) sontsystématiquement achetés et le service dispose de moyens detest et de qualification de leurs performances.Mais nous travaillons également sur le développement dedétecteurs diamant utilisés pour le contrôle faisceau oucomme cibles actives dans certaines expériences. Cesdiamants, fabriqués par pulvérisation cathodique, sont achetésbruts chez elementsix™ et le laboratoire élabore les masquesd’évaporation permettant de les adapter précisément auxbesoins (généralement des strips X et Y avec anneau degarde). La technique très particulière de tenue del’évaporation nécessite la mise en œuvre de dépôts primaired’accrochage et de recuit du détecteur afin d’augmenter larobustesse de la métallisation.
Acquisition numérique FASTER
Depuis quelques années, une action de recherche et
développement est menée au sein des services techniques dulaboratoire pour développer un nouveau système d’acquisitionde données numériques, ce projet est nommé FASTER(http://faster.in2p3.fr). En effet, les détecteurs de physiquenucléaire développés au laboratoire sont de plus en plusperformants et nécessitent une acquisition capable d’exploiterces performances.Les systèmes d’acquisitions en physique nucléaired’aujourd’hui voient leurs performances limitées en raison destechnologies utilisées (utilisation de bus parallèle,reconstruction de l’événement par la technique du tempsmort commun, réalisation des fonctions de mesure de charge,mesure d’amplitude et mesure de temps en analogique).
Le but de FASTER est de développer un système d’acquisition,de contrôle et commande dont les contraintes principalessont les suivantes :
Fig. 3 : Chambre d’ionisation à localisation par stripsDOSION (Radiobiologie)
Fig. 4 : Chambre d’ionisation avec Pad central d’étalonnagepour le contrôle de la
radiothérapie
Fig. 5 : Diamant à strip –Faisceaulogie SPIRAL2
Une plate-forme modulaire entièrement configurable etextensible (standard de module).
La reprogrammation à volonté et à distance des FPGA. La communication montante, descendante à très hautdébit.
La synchronisation de l’ensemble du système par unedistribution d’horloge.
La possibilité d’extension du système. Une infrastructure électronique basée sur des standardsindustriels.
Le traitement numérique des signaux.
De multiples niveaux de décisions (trigger local,régional, global).
Une grande variété de modes de décision (sélections,filtrages, contre-réactions, traitements en ligne).
L’introspection du système. Une topologie d'arbre n-aire. Aucun a priori sur l'expérience.
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Pour le développement de ce système, nous utilisons lescompétences en électronique du service instrumentation pour laconception et le développement de cartes électroniques à basede FPGA. Le développement du programme de ces FPGA enVHDL et le développement des algorithmes temps réels sontréalisés par le service. La partie logicielle de ce projet est réaliséepar le groupe informatique qui utilise les langages ADA etPython.La grande modularité du système, les performances et l’utilisationdu standard microTCA permettent au projet FASTER derépondre rapidement aux différentes exigences des utilisateursrépartis dans plusieurs pays :
Belgium : Université de Leuven,
France : Université de Paris-Sud, CIMAP, LPC-Caen, IPHC, CEA,
Spain : Université de Granada,
Switzerland : PSI, CERN (Isolde),
USA : CENPA, Argonne, MSU.
Fig. 6 : Chassis microTCA avec 6 cartes FASTER
En conclusion, le système FASTER donne aux chercheurs un outil performant facile d’emploi qui leur permet d’accéder à denouvelles informations sur les phénomènes de physique.
Le contrôle et commande des dispositifs expérimentaux
Le service instrumentation conçoit et développe les automatismes et le contrôle et commande nécessaire aux expériencesde physique.Les automates programmables sont généralement utilisés pour la gestion des enceintes à vide et l’injection ou la circulation desgaz utilisés par les détecteurs gazeux.Un logiciel de contrôle et commande léger et flexible a été développé par le service instrumentation il y a quelques années. Ilpermet de piloter à distance des équipements hétérogènes tels que des alimentations, des pompes à vide, des générateurs,etc… Ce logiciel a permis de piloter le piège de Paul situé sur la ligne « LIRAT » au GANIL et le démonstrateur du RFQ-Cooler pour le projet SPIRAL2.Ces deux dernières années, le logiciel a été complété par une couche de haut niveau pour l’interface homme-machine.
Les techniques du vide
Les activités des techniques du vide au laboratoire concernent l’étude des besoins pour les expériences, la gestion desappareils de production et de mesure, la formation des utilisateurs et le contrôle d’étanchéité des ensembles mécaniques.Le démonstrateur du RFQ-Cooler pour SPIRAL 2 est l’exemple typique d’une étude complète d’un dispositif de vide poussédans lequel nous injectons un gaz. L‘étude, le dimensionnement des systèmes de pompage et le calcul des pressions pour lesdispositifs expérimentaux font partie des activités en matière de vide. Dans le cas d’injection de gaz dans un volume faisantpartie d’un assemblage d’enceintes sous vide, il est important de calculer les pertes de charge ou conductances induites par leséléments mécaniques d’interconnexion de ces enceintes.
Fig. 7 : Interface de gestion du vide du démonstrateur de refroidisseur d’ions pour SPIRAL2
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Ces calculs permettent de déterminer les pressions attenduesdans les différentes parties de cet assemblage et de dimensionnerles systèmes de pompage.Le principal défi de cette installation vient du fait que le gaz estinjecté en présence d’ions radioactifs. Ce gaz peu devenirpotentiellement radioactif, il est donc stocké puis contrôlé avantd’être éliminé. Or, l’infrastructure de l’accélérateur ne possèdepas la capacité de stockage nécessaire pour une période defonctionnement complète, nous avons étudié un système de« recyclage » de l’hélium permettant de réutiliser le gaz rejetépar les pompes à vide.Pour réaliser des étuvages sous vide, nous avons conçu uneenceinte ultravide équipée de cordons chauffants. Ils sont reliés àun système de régulation dont le rôle est d’amenerprogressivement cette enceinte à une température de 150 °C.Le maintien de cette température, pendant quelques jours, activela désorption de la vapeur d’eau contenue dans les matériauxplacés sous vide, permettant ainsi un gain de temps de pompagenon négligeable pour atteindre la pression limite (qq 10-10 mbar).Cette vapeur d’eau peut également être apportée par l’injectionde gaz sous vide nécessaire dans certaines applicationsexpérimentales. Dans ce cas, afin de maintenir le taux de vapeurd’eau le plus bas possible, nous utilisons des pièges froids. Cesont des réservoirs remplis d’azote liquide dont les paroisplacées sous vide permettent de fixer temporairement lesmolécules condensables.
Spectrométrie des rayonnements Xet gamma
Une activité de spectrométrie X et gamma fonctionne en
permanence au Laboratoire. Nous disposons de deux détecteursGermanium hyper-purs et d’un détecteur Silicium-Lithium poureffectuer respectivement de la spectrométrie de photons gammaet X. Avec ces trois dispositifs, nous effectuons des mesures defaibles concentrations de radioéléments ou d’éléments stablesdans des échantillons liquides ou solides. Pour mettre enévidence des éléments stables, nous utilisons la technique defluorescence X avec deux sources d’excitation possibles : unesource radioactive d’américium ou un générateur de rayons X.Les intérêts de ces mesures sont nombreux et variées. Ilsconcernent les domaines de l’environnement, l’industrie, labiologie, etc…Applications spécifiques :
Détection de rayonnements gamma : identification desradionucléides émetteurs gamma présents dans deséchantillons et mesure de la radioactivité associée.
Détection de rayonnements X : mesure non destructivequalitative et quantitative de concentration d'élémentsprésents dans des échantillons liquides ou solides.
Applications possibles dans les domaines de la détection. Recherche et contrôle de la pollution. Secteur industriel : identification et concentration d'élémentsdans la matière
Fig. 8 : Enceinte pour les tests en vide poussé.
Fig. 9 : Exemple de spectre gamma avec un détecteur Germanium hyper pur
Fig. 10 : Étude de l’iode dans les algues par fluorescence X
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Missions
La documentation a en charge la gestion de
l’information scientifique et technique (IST) dans sonensemble. Fonction soutien de la recherche, son rôle estd’accompagner les chercheurs dans leurs recherchesbibliographiques et d’optimiser l’accès aux différentesressources documentaires. Les actions de la documentationsont également liées à l’exploitation des données de larecherche. Les publications scientifiques produites par lelaboratoire sont disponibles par notre plate-forme destockage de données institutionnelles en libre accès :HAL−IN2P3, via notre collection hal.in2p3.fr/LPC-CAEN/fr/.Ce mode de diffusion apporte une visibilité optimum auxpublications. La production d’indicateurs bibliométriques,essentielle pour l’évaluation de nos tutelles, du laboratoire etdes chercheurs est l’aboutissement de la chainedocumentaire telle qu’elle est organisée au laboratoire.
Fontionnement
La bibliothèque du laboratoire dispose d’un fondsdocumentaire spécialisé dans notre thématique derecherche. Nos collections font partie du catalogue commundes bibliothèques de l’IN2P3, géré par un système de gestionde base de données en licence libre. Nos principalesressources documentaires sont négociées par nospartenaires (CNRS, ENSICAEN et Université de Caen Basse-Normandie). L’accès à la bibliothèque est réservé auxpersonnels et étudiants du laboratoire.Le LPC dispose d’un outil collaboratif pour la gestion desdocuments techniques, (GDT) qui s’intègre dans leprocessus "Qualité - Projet" de l'IN2P3. En 2013, s’est initiéle remplacement de l’outil actuel (EDMS) par (ATRIUM), uninformaticien renforce désormais l’action de gestion localepar la documentaliste.
Réseau DEMOCRITE
Depuis 1986, les documentalistes de l’IN2P3
travaillent en réseau et mettent en commun leurs ressourcesau profit de la communauté scientifique de l’institut. Leréseau représente 19 personnes sur toute la France. Lesrencontres annuelles du réseau ont eu lieu au CPPM deMarseille en 2013. Sandrine Guesnon représente le réseauDEMOCRITE depuis octobre 2012.
Communication
Depuis de nombreuses années, Le LPC s’engage
fortement pour le transfert de connaissance vers le grandpublic (cf «Manisfestations grand public»). Dans ce sens, uneCellule Communication constituée de 10 personnes élaborel’ensemble des ces actions avec l’appui du personnel(cf «Organigramme»).Correspondante Communication auprès de nos tutelles etde nos partenaires régionaux, Sandrine Guesnon coordonnela Cellule Com, exploite l’information à son maximum versdifférents supports (sites web, rapports, brochures etc.) etdresse les bilans annuels. Olivier Lopez (Chercheur CNRS)assure les relations scientifiques et Julien Gibelin (Maitre deconférence) les relations culturelles.
Laboratoire de physique corpusculaire
http://www.lpc-caen.in2p3.fr
Portail IST (IN2P3)http://documentalistes.in2p3.fr
Archives Ouverteshttp://hal.in2p3.fr
Outilshttp://koha3.in2p3.frhttp://edms.in2p3.fr
Ressourceshttp://bibliosciences.inist.frhttp://scd.unicaen.fr/
Laboratoire de physique corpusculaire
http://www.lpc-caen.in2p3.fr
Portail IST (IN2P3)http://documentalistes.in2p3.fr
Archives Ouverteshttp://hal.in2p3.fr
Outilshttp://koha3.in2p3.frhttp://edms.in2p3.fr
Ressourceshttp://bibliosciences.inist.frhttp://scd.unicaen.fr/
DOCUMENTATION
S. Guesnon
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QUALITÉ ET SOUTIENAUX PROJETS
A. Cauvin, P. Laborie
Les projets dans lesquels le laboratoire s’impliquesont de plus en plus complexes et il devient de plus en plusdélicat de trouver des sources de financement pour cesmêmes projets.C’est ainsi que plusieurs actions de type qualité sont menéesau laboratoire depuis plusieurs années afin de réduire nosrisques.
Actions
En début de chaque année, nous organisons uneréunion où les responsables de groupe et de projetsprésentent leurs besoins pour l’année à venir en« équivalents temps plein » au niveau des servicestechniques. Cette réunion est ouverte à l’ensemble dupersonnel du laboratoire, elle est suivie d’une analyseréalisée par la direction et les responsables de serviceconcernés et animée par le responsable technique dulaboratoire (remarque : ce groupe est appelé la Cellule deSoutien aux Projets du laboratoire). Cette démarched’anticipation permet de « déminer » les problèmes avantqu’ils n’arrivent. En fin de chaque année, nous faisons uncomparatif entre ce qui avait été demandé lors de cetteréunion et ce qui a été finalement réalisé. Les écarts sontensuite analysés.
Nous organisons, sur demande de la direction, des
« revues d’opportunité » pour les nouveaux projets dulaboratoire dans le but d’identifier les risques associés à cesdifférents projets. Ces revues sont un des outils qui aiderontla direction à décider de son engagement ou non-engagement dans un nouveau projet.
Nous proposons notre aide aux porteurs de projet
lorsqu’ils déposent une demande de financement en nousassurant que la structuration du projet répond bien auxattentes des agences de financement.
Enfin, nous participons à des audits dans le cadre dedifférents projets (exemple : SPIRAL2) et sommes membresdu réseau qualité de l’IN2P3.
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HYGIÈNE ET SÉCURITÉ
Organisation
La cellule HSE (Hygiène, Sécurité et Environnement) seréunit pour discuter des problèmes rencontrés et desaméliorations à apporter. Elle est composée du Directeur,des Personnes Compétentes en Radioprotection (PCR), duresponsable infrastructure et de l’Assistant de prévention.
Actions
Vérifications périodiques : engins de levage, détection degaz (O2)
Suivi des registres d’hygiène et sécurité et du programmeannuel d’actions de prévention
Procédure d’accueil pour les nouveaux arrivants aulaboratoire : présentation de l’organisation de l’hygièneet de la sécurité, des risques et des moyens deprévention
Gestion des diverses habilitations de sécurité dupersonnel
Radioprotection
La Personne compétente en radioprotection supervise
l'activité liée aux rayonnements ionisants du laboratoire:gestion des sources, formation à la radioprotection dupersonnel salarié et non salarié, suivi de la dosimétrieambiante et individuelle, expertise du site. relationLa PCR assure le lien avec la Médecine du Travail, lesautorités officielles telles que l’ASN et l’IRSN ainsi quel lesorganismes de contrôle comme l’Apave.La PCR est nommée par le directeur du laboratoire etintervient auprès de celui-ci pour l’orienter vers le respectde la réglementation et vers la mise en conformité deslocaux.
J.C. Angélique (PCR), J.L. Gabriel (PCR adjoint), C. Vandamme (Assistant de Prévention)
75
Enseignement
Formation par la recherche
Formation permanente
Valorisation
Actions de communication
Conférences et rencontres scientifiques
DIFFUSION DU SAVOIR
76
ENSEIGNEMENT
Services d’enseignement assurés par les membres du LPC
En avril 2014, le laboratoire accueille 18 enseignants-
chercheurs titulaires et 3 doctorants effectuent une activitécomplémentaire d’enseignement. Leurs activités sontrattachées aux formations de l’Université de CAEN-BasseNormandie (5 professeurs, 8 maîtres de conférences, 2doctorants) ou de l’école d’ingénieurs ENSICAEN (2professeurs, 3 maîtres de conférences, 1 doctorant).
Responsabilités au sein de l’UCBN
Les professeurs et maîtres de conférences du LPC
interviennent dans toutes les années des cycles Licence etMaster. Outre leurs interventions dans des champsdisciplinaires correspondant aux thématiques de recherchedu laboratoire (physique subatomique, physique quantique etstatistique), ils participent également à l’enseignement de laphysique générale (en particulier dans le cadre de la licencede Biologie et des préparations aux concours del’enseignement en Physique-Chimie). Un maître deconférence effectue intégralement son serviced’enseignement dans le département « Mesures Physiques »de l’IUT de Caen et plusieurs enseignants-chercheursinterviennent dans les formations dispensées à l’antenne deCherbourg (L1 & L2 Physique-Chimie, Licencesprofessionnelles « Maintenance en milieu nucléaire » et« Assainissement, gestion des déchets et démantèlement enmilieu nucléaire », filière « Opérations nucléaires » de l’écoled’ingénieurs ESIX rattachée à l’Université).
Un professeur assure la direction des études de la Licence,mention « Physique « et la direction du département« Physique-EEA » de l’Université. Il est également membredu conseil de l’UFR Sciences. Deux autres professeurs sontrespectivement en charge du Master « Noyaux, Atomes,Collisions » et de la Licence professionnelle « Maintenanceen milieu nucléaire ».
Responsabilités au sein de l’ENSICAEN
Les professeurs et maîtres de conférences enseignent
dans les trois années de formation de l’ENSICAEN. Ilsassurent essentiellement des cours, travaux dirigés etpratiques en physique nucléaire fondamentale et appliquée(neutronique, instrumentation, imagerie…), mais sont aussien charge d’enseignements généraux (physique quantique etphysique statistique). Plusieurs techniciens et ingénieurs duLPC sont également associés à ces enseignements au traversde conférences et de projets en laboratoire. Les enseignants-chercheurs assurent par ailleurs la responsabilité de l’option« Ingénierie nucléaire » et ils sont fortement impliqués dansla filière « Instrumentation avancée ». Enfin, plusieurs coursde troisième année sont mutualisés entre l’ENSICAEN et leMaster de Physique « Noyaux, Atomes, Collisions » del’UCBN.
Nouveaux diplômes
Récemment, plusieurs enseignants-chercheurs et
chercheurs CNRS, membres du LPC et plusieurs autresinstitutions, ont créé un Master international centré sur lesapplications des sciences du nucléaire. Ce nouveau diplôme,co-accrédité avec l’école d’ingénieurs des Mines de Nantes« EMN », a démarré en Septembre 2012 sous laresponsabilité, à Caen, de deux enseignants-chercheurs duLPC.
Enseignements dispensés dans d’autresorganismes
Plusieurs interventions occasionnelles sont réalisées
par des professeurs et chercheurs du LPC dans différentsMasters des universités parisiennes.
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FORMATION PAR LE RECHERCHE
Pendant la période 2012-2013, sept doctorants ont
soutenu leur thèse et 3 habilitations à diriger des recherchesont été présentées. Actuellement, dix étudiants préparent leurdoctorat au laboratoire.
Thèses
Sénoville M.Développement d'un nouveau multi-détecteur de neutrons(2013-12-13)
Couratin C.Mesures de précision avec LPCTrap et développementstechniques à GANIL : corrélation angulaire bêta-neutrino (aβν)et probabilité de shakeoff dans la décroissance de l’6He1+, étudede la production de nouveaux faisceaux à SPIRAL (2013-10-18)
Legouée E.Étude systématique de la dynamique et de la thermodynamiquedes systèmes nucléaires symétriques ou quasi-symétriquesétudiés avec le multidétecteur INDRA par des méthodesprobabilistes nouvelles (2012-10-17)
Boussaïd R.Etude et développement d’un refroidisseur radiofréquence àgaz tampon pour des faisceaux radioactifs de très hautesintensités (2012-12-12)
Bonnard J.Approches Monte-Carlo quantiques à chemins contraints pourle modèle en couches nucléaire(2012-12-07)
Leredde A.Collisions ion-atome sur cible préparée par laser : étude àhaute résolution du processus de simple capture(2012-1-15)
Pierre E.Développement et optimisation d’un système de polarisation deneutrons ultra froids dans le cadre d’une nouvelle mesure dumoment dipolaire électrique du neutron (2012-03-26)
HDR
Marques F.M.A la recherche d'un femtomêtre (19/01/2012)
Fléchard X.La spectroscopie d'ions de recul en Physique Atomique et enPhysique Nucléaire: Applications à l'étude des collisions à basseénergie et à la mesure de la corrélation b-n en décroissance b(13/12/2012)
Fontbonne J.M.Contrôle faisceau en radiothérapie & hadronthérapie(18/12/2012)
Stages
Nous accueillons également de nombreux stagiaires de
formations diverses, scientifiques et techniques. Les stages dePhysique regroupent des étudiants de Master, Ecolesd’ingénieurs, Licence. Les stages techniques concernent desélèves provenant des Ecoles d’ingénieurs, BTS, IUT, collèges etde lycées par les stages « Découverte du MondeProfessionnel ».Chaque année, des stagiaires Janus sont accueillis pendant 1mois au cours duquel une école d’été, poursuivant l’objectif deprésenter la physique subatomique, est organisée encollaboration avec le Ganil.Voici le tableau de ces différents stages concernant la période2012 – 2013 :
2012 2013
Stage « découverte »
9 13
Licence L1, L2 & L3
8 13
Ecoles d’ingénieur 1 3
Master M1 & M2 5 17
Janus 6 0
DUT / BTS 1 2
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Actions de formation suivies par les agents du LPC Caen durant la période 2012 - 2013
AnnéeNombre de jours de
formation
Nombre de personnes
formées
(toutes catégories
confondues)
Nombre de jours de
formation par
personne
(moyenne)
Proportion
d’ITA+ITARF
formés
2012 292 32 9,13 32/38 = 84,21 %
2013 237 51 4,65 33/39 = 84,62 %
Actions de formations durant l’année 2012 triées par organismes financeurs
FINANCEMENT INTITULE DE STAGENOMBRE DE
PARTICIPANTS
AUTRES L'ANALYSE BIBLIOMÉTRIQUE, L'ÉVALUATION ET LE SUIVI DES ACTIVITÉS 1 pers
DR19 ANGLAIS COURS FONDAMENTAUX 10 pers
ANGLAIS EN IMMERSION 2 pers
CFAO MASTERCAM 3D 3 pers
ECRITURE DE DRIVERS SOUS LINUX 3 pers
HYGIENE ET SECURITE EN LABORATOIRE 2 pers
MISE A JOUR SUR LA CHAINE DE COTES 2 pers
PARCOURS DE FORMATION À L'ENCADREMENT 2 pers
PREPARATION AUX CONCOURS INTERNES 2 pers
RECYCLAGE PCR 1 pers
ECOLE JOLIOT CURIE ECOLE JOLIOT-CURIE 4 pers
ECOLES ET STAGES
IN2P3ECOLE MECATRONIQUE 1 pers
METHODOLOGIE ET OUTILS D'OPTIMISATION EN DEVELOPPEMENT
LOGICIEL 1 pers
OUTILS DE LA CONDUITE DE PROJET 1 pers
A. Leconte
FORMATION PERMANENTE
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FINANCEMENT INTITULE DE STAGENOMBRE DE
PARTICIPANTS
IAO/CAO IN2P3 ENCOUNTER RTL COMPILER 1 pers
LOGICIEL DE CALCUL ANSYS 2 pers
VIRTUOSO CONNECTIVITY DRIVEN LAYOUT 1 pers
VIRTUOSO LAYOUT DESIGN BASICS 1 pers
IN2P3 ANSYS FLUIDE THERMIQUE 1 pers
COLLOQUE INFORMATIQUE IN2P3 - IRFU 2 pers
JOURNEE DES NOUVEAUX ENTRANTS EOLE 1 pers
SOS : SCHOOL OF STATISTICS 1 pers
TRANSPORT DE MARCHANDISES DANGEREUSES 2 pers
LABORATOIRE ACQUISITIONS ET ACCÈS AUX RESSOURCES ÉLECTRONIQUES : QUEL FUTUR ? 1 pers
CONCEPTION DE CARTES ELECTRONIQUES 1 pers
SEMINAIRE IN2P3 PCR 2 pers
RESEAU DES
ELECTRONICIENSELECTRONIQUE NUMERIQUE PROGRAMMABLE 2 pers
SANS FRAIS CALCUL D'INCERTITUDE ET TRAITEMENT DES DONNEES 2 pers
CONNAISANCES DE BASE SUR LA RADIOPROTECTION A GANIL 6 pers
DOSSIERS ANNUELS SIRHUS 1 pers
ECOLE DE LA PHYSIQUE AU DÉTECTEUR 1 pers
GESLAB : CENTRALISATION DES BASES XLAB 3 pers
GUIDE D'EVACUATION 4 pers
JOURNEES VLSI-PCB-FPGA-IAOCAO IN2P3 3 pers
LANGAGE PYTHON INITIATION 1 pers
LES OUTILS DE LA CONDUITE DE PROJET 8 pers
L'IST SANS BIBLIOTHÈQUE 1 pers
MÉTHODOLOGIE DE L'APPRENTISSAGE DE L'ANGLAIS (TD) 1 pers
PHOTOSHOP AVANCÉ 1 pers
PRINCIPES DE MÉTHODOLOGIE DE L'APPRENTISSAGE DE L'ANGLAIS (CM) 2 pers
QSYS ALTERA 2 pers
RECYCLAGE SST 1 pers
ROOT POUR DEBUTANT 3 pers
TECHNIQUES DU VIDE POUR UTILISATEURS 2 pers
VIDE DETECTION DE FUITES 1 pers
UNIVERSITE ANGLAIS A L'UNIVERSITE 1 pers
EVALUATION DE LA RECHERCHE SCIENTIFIQUE 1 pers
GESTION DE PROJETS INFORMATIQUES 1 pers
GRAAL : LOGICIEL DE GESTION DE LA RECHERCHE 1 pers
INITIATION SST 1 pers
LABVIEW 1 pers
RECYCLAGE PCR 1 pers
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Actions de formations durant l’année 2013 triées par organismes financeurs
FINANCEMENT INTITULE DE STAGENOMBRE DE
PARTICIPANTS
AUTRES ECOLE SUR LES BONNES PRATIQUES ORGANISATIONNELLES POUR LES ASR 1 pers
CNRS DÉVELOPPEMENT COLLABORATIF POUR LE LOGICIEL LIBRE (ENVOL) 1 pers
GÉNÉRALISER L'ACCÈS OUVERT AUX RÉSULTATS DE LA RECHERCHE 1 pers
DR19 13 EME RENCONTRE NATIONALE DU RESEAU DES MECANICIENS 5 pers
ANGLAIS COURS FONDAMENTAUX 6 pers
ANGLAIS EN IMMERSION 1 pers
FORMATION AGATE 4 pers
FORMATION ROOT 1 pers
INITIATION HABILITATION ELECTRIQUE 4 pers
JOURNEE TECHNIQUE DECOUPE JET D'EAU 3 pers
JOURNÉES JDEV 1 pers
JOURNEES JRES 2 pers
JUSTIFICATIONS ET AUDITS DES PROJETS EUROPEENS 1 pers
LANGAGE VHDL POUR LA CONCEPTION D'ASIC ET DE FPGA 1 pers
LE BUS RAPIDIO 2 pers
PARCOURS DE FORMATION A L'ENCADREMENT 2 pers
PREPARATION AUX CONCOURS INTERNES 2 pers
PREPARER SON DEPART A LA RETRAITE 1 pers
PREPARER SON ENTRETIEN ANNUEL D'ACTIVITES 1 pers
RECYCLAGE SAUVETEUR SECOURISTE DU TRAVAIL 2 pers
RÈGLES DE CONCEPTION ET DE CONSTRUCTION DES REP 1 pers
RENCONTRES DU RÉSEAU RÉGIONAL GRAND OUEST DES PCR 2 pers
REUNION CORRESPONDANTS FORMATION 1 pers
IAO/CAO IN2P3 ALLEGRO PCB EDITOR INTERMEDIATE TECHNIQUES V16 1 pers
ANSYS NON LINEAIRE 2 pers
WORKSHOP FPGA SYSTEM PLANNER 1 pers
IN2P3 ANALOG-ON-TOP MIXED-SIGNAL IMPLEMENTATION VIC6.1.5 1 pers
CONCEPTION DE CARTES ELECTRONIQUES AVEC BIBLIOTHEQUES IN2P3 1 pers
ECOLE DU DETECTEUR A LA MESURE 1 pers
ECOLE IN2P3 DE MICROELECTRONIQUE 1 pers
ECOLE JOLIOT-CURIE 1 pers
ECOLE TECHNIQUES DE BASE DES DETECTEURS 1 pers
REUNION CORRESPONDANTS FORMATION 1 pers
VIRTUOSO AMS DESIGNER 1 pers
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FINANCEMENT INTITULE DE STAGENOMBRE DE
PARTICIPANTS
LABORATOIRE GEANT4 1 pers
JOURNEES JRES 1 pers
RÈGLES DECONCEPTION ET DE CONSTRUCTION DES REP 1 pers
RESEAU DES
MECANICIENSUSINAGE DES MATERIAUX DIFFICILES 3 pers
SANS FRAIS 22 EME RECONTRE DU RESEAU REGIONAL GRAND OUEST DES PCR 2 pers
CONDUIRE UN ENTRETIEN ANNUEL D'ACTIVITES 1 pers
CONNAISSANCE DE BASE SUR LA RADIOPROTECTION A GANIL 17 pers
FORMATION DES PRESIDENTS ET MEMBRES DE JURY CONCOURS INTERNES 1 pers
FORMATION DES PRESIDENTS ET MEMBRES DE JURY DE CONCOURS EXTERNES 1 pers
FORMATION INITIALE SST CNRS 1 pers
FORMATION MEMBRES DU CRHSCT (1ÈRE PARTIE) 1 pers
RECYCLAGE SST UNIVERSITE 2 pers
RENCONTRES QUALITE QUARES 1 pers
RESEAU REGIONAL GRAND OUEST DES PCR 4 pers
UNIVERSITE ANALYSE SISMIQUE DES STRUCTURES 1 pers
ANGLAIS COURS FONDAMENTAL 1 pers
INITIATION SST 1 pers
MAINTENANCE SUR DES MATERIAUX POUVANT CONTENIR DE L'AMIANTE 1 pers
Participation du laboratoire à l’offre de formation permanente
2012 Nbre pers
LES OUTILS DE LA CONDUIT DE PROJET À PARIS 1 pers
LES OUTILS DE LA CONDUIT DE PROJET (SESSION INTERNE AU LABORATOIRE) 1 pers
FABRICATION MÉCANIQUE ET SOUDURE (SESSION INTERNE AU LABORATOIRE) 1 pers
« ROOT » POUR DÉBUTANTS (2 SESSIONS) 1 pers
RETOUR D’EXPÉRIENCE : MESURE DE TEMPS AVEC UN FPGA (ÉCOLE SYSTÈMES
ÉLECTRONIQUES)1 pers
LES OUTILS DE LA CONDUIT DE PROJET (SESSION INTERNE AU LABORATOIRE) 1 pers
FABRICATION MÉCANIQUE ET SOUDURE (SESSION INTERNE AU LABORATOIRE) 1 pers
« ROOT » POUR DÉBUTANTS (2 SESSIONS) 1 pers
2013
ECOLE “TECHNIQUE DE BASE DES DÉTECTEURS” (ÉLECTRONIQUE ANALOGIQUE) 1 pers
« ROOT » POUR DÉBUTANTS (2 SESSIONS) 1 pers
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A. Leconte
VALORISATION
La principale tâche du Correspondant Valorisation est de
détecter les savoir-faire du laboratoire afin d’intéresser le secteur industriel pour différents développements.
Les sujets actifs de valorisation durant la période 2012 – 2013sont les suivants :
Après l’accord de développement entre le LPC et le groupeAreva signé en 2011, un démonstrateur de dosimètre actifextrémités a été réalisé et livré à la filiale Melox d’Areva. Unaccord de license d’exploitation des connaissances a été signéentre Areva et l’Ensicaen le 03 juillet 2012. Le transfert versl’industrialisation est pris en compte par Melox avec consultanceLPC. Dans ce contexte, la société APVL de Tours qui fabriqueraet commercialisera les dosimètres a été sollicitée par Melox.Dans ce cadre, le LPC assure l’assistance technique à Mélox aucours de ce processus industriel.
Le projet d’instrumentation Faster qui porte sur une acquisitionde données entièrement numérique est passé durant cettepériode à une phase de production de différents ensemblesd’acquisition après avoir validé les algorithmes de traitementADC, QDC et TDC. Ainsi, les cartes électroniques suivantesont été vendues :
1 au format NIM à l’Université de Leuven (Belgique) 5 Siroco-V2 à l’Université Paris-Sud 1 au format NIM au CIMAP à Caen 1 Siroco-V2 à l’IPHC de Strasbourg 1 châssis µTCA 32 voies et 3 cartes format NIM au CEA 1 Siroco-V2 à l’Université de Grenade (Espagne) 1 châssis µTCA 12 voies au PSI (Suisse) 1 châssis µTCA 8 voies au CERN (Isolde) (Suisse) 1 châssis µTCA 20 voies à CENPA, Argonne (USA) 1 Siroco-V2 au MSU (USA)
Un contrat de collaboration de recherche a été signé entre leLPC et la société IBA en décembre 2013. Il définit le cadre d’unprojet qui porte sur l’étude de la réponse de chambresd’ionisation sous faisceau de protons à haut débit. Dans cecontexte, une thèse financée par la région dont le sujet est decomprendre les mécanismes de création et de collection decharges dans les chambres d’ionisation a démarré au 1er octobre2012.
La société CERAP d’ingénierie et de conseil en radioprotectionet sureté nucléaire va signer prochainement avec le LPC uncontrat de collaboration de recherche afin de valider par le LPCdes mesures effectuées par cette société.
Une prestation de service entre la société Piercan spécialiséedans la fabrication de gants utilisés pour la manipulation deradioéléments et le LPC a été signée en juin 2013 afin de testerles différentes matières utilisées dans la fabrication de ces gants.Dans ce contexte, une formation sur la radioprotection estégalement assurée par le LPC.
Vulgarisation scientifique
Le billotron est un outil de vulgarisation scientifique qui décrit defaçon macroscopique l’expérience de Rutherford. Cedéveloppement a obtenu en 2010 le premier prix du concours« têtes chercheuses » lancé par l’association « Relais deSciences » et la fondation Schlumberger. Une enveloppe Soleau aété déposée à l’INPI (Institut National de la PropriétéIntellectuelle) afin de protéger ce développement contre lacopie.
Le jeu Nucléus permettant de comprendre les voies dedésintégration des éléments instables a été présenté lors de lafête de la science 2011. Ce jeu a été protégé de la même façon àl’INPI par une enveloppe Soleau.
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O. LopezAvec la participation de l’ensemble du laboratoire
ACTIONS DE COMMUNICATION
Conférences GRES
Le Groupe de Réflexion sur l’Enseignement des Sciences
(GRES) rassemble des enseignants-chercheurs et chercheurs enPhysique, Mathématiques, Chimie, Biologie et Sciences de laTerre de l’ENSICAEN et de l’Université de Caen Basse-Normandie. Il résulte du développement d’une structure initiéeau niveau national par l’IN2P3/CNRS et la DSM/CEA, le GREPS.La particularité du groupe mis en place à Caen est de regroupernon seulement les physiciens nucléaires mais tous les domainesscientifiques abordés au niveau local. L’objectif est de pallier à labaisse notable observée depuis quelques années des effectifs dansles filières scientifiques (au niveau aussi bien des lycées que ducycle supérieur). Pour atteindre cela, le GRES développe desrelations entre les enseignants du Supérieur, les chercheurs et lescollègues enseignants du secondaire. Cette action prolonge etcomplète (par les thèmes plus variés) les conférences NEPAL(conférences dans les lycées) organisées par l'IN2P3 et le CEA.
Bilan 2012-2013
Dans la région Basse-Normandie, nous avons ainsi plusieursconventions de partenariat avec des établissements duSecondaire (lycées), afin de formaliser un protocoled’intervention d’au moins 2 conférences par établissement dans
l’année, ainsi que de fournir une aide logistique pour les TPE(Travaux Personnels Encadrés). A l’heure actuelle, le groupepropose plus de 15 conférences dans des domaines aussi variésque les rayonnements ionisants, les énergies, l’atome, la cellule,les mesures,… illustrant ainsi la richesse du tissu de recherchebas-normand. Ces interventions sont illustrées ci-dessus.
Depuis quelques années nous associons ces conférences avec laprésentation d'une partie des modules présentés à la Fête de laScience par une ou plusieurs personnes, notamment par desdoctorants.
Fête de la science
La Fête de la Science est une action pilotée par le Ministère
de la Recherche, qui est relayée par les CCSTI en région ; enBasse-Normandie, Relais d’Sciences remplit cette mission. Cettemanifestation se déroule durant une semaine traditionnellementautour de la mi-Octobre et permet au grand public de découvrirou mieux connaître les organismes de recherche et lesassociations à caractère scientifique. Pour le laboratoire,l'opération est construite autour d'un parcours didactique sur laradioactivité.
Vers l’infini et au-delà
L’énergie, un enjeu pour la recherche et pour la société
Interaction rayonnement matière et applications
Physique et santé (hadronthérapie)
La ballade des électrons
Le rayonnement, comprendre et évaluer les risques
Paroles d’atomes
La communication au Laboratoire s’organise autour de 3 grands thèmes, qui regroupent des actions vers des publics spécifiques,
les conférences GRES (lycées), la Fête de la Science (tous publics) et les actions spécifiques (publics variés). Nous entendons icipar communication toute action dont le but est de promouvoir les sciences en général et notre domaine de recherche en particulier, àsavoir la Physique Nucléaire auprès du grand public. Pour répondre à ces objectifs, le Laboratoire s’est engagé depuis longtemps dansdes opérations permettant d’y répondre concrètement. Dans ce qui suit, nous faisons un état des lieux de ce qui a été réalisé durant lapériode 2012-2013.
84
Autres actions
En marge des actions déjà mentionnées, le Laboratoire organise ou participe à d'autres opérations qui ne rentrent pas dans le
cadre récurrent exposé plus haut. Ces actions sont répertoriées dans le tableau ci-dessous :
Parcours culturels scientifiques
Organisés par Relais d'sciences et le Rectorat de l'Académie de Caen, avec le soutien financier de la Région Basse-
Normandie, les PCS (Parcours culturels scientifiques) mobilisent les moyens humains, techniques et financiers pour accompagnerles enseignants dans la réalisation de leurs projets de culture scientifique et technique. Le LPC est bien sûr impliqué sur les PCS,plusieurs projets scientifiques ont été menés sous forme d’ateliers suivis par un groupe d'élèves de Lycée durant une année.Classes de SEGPA (Section d’Enseignement Général et Professionnel Adapté) :
Collège Jean Racine d’Alençon.Classe de 5ème
Thème abordé : Source de lumière.
Collège Jean Rostand d’Argentan.Classe de 4ème
Thème abordé : Big Bang.
Collège Henri Sellier de Colombelles.Classe de 4ème
Thème abordé : Les différents types de rayonnement.
Organisation au niveau du laboratoire
Depuis 6 ans, le laboratoire s'est doté d'une cellule de communication, qui regroupe un petit nombre de personnes impliquées
à différents niveaux dans les actions de communication au sens large : documentation, séminaires, site internet, formationpermanente, responsable communication. Cette cellule se réunit environ 4 fois par an et définit les actions de communication àmener par le laboratoire. Elle est présidée par le directeur ou le directeur adjoint et coordonnée par la documentaliste dulaboratoire.
Les correspondants communication sont :Olivier Lopez (Relations Scientifiques)Sandrine Guesnon (Gestion de l’information – Web)
Action Type Nombre d’actions
Audience Nombre de public
Personnel LPC
Expo « Zoom »
Expo 2 (2012) Collèges, Lycées, Familles
400-500 3
Visites du laboratoire
Visite 5 (2012)9 (2013)
Collège, Grandes écoles,
Université
400-500 3
Atelier du chercheur
Présentation 1 (2012)1 (2013
Tous publics 100 2
Forum des métiers
Discussion 1 (2012)1 (2013
Tous publics 400-500 2
Stages découverte
Formation 4 (2012)3 (2013)
Collèges 913
6
85
CONFÉRENCES ET RENCONTRES SCIENTIFIQUES
Nuclear structureTransfer and knockout to probe continuum states of light very neutron rich nuclei»,N.A. OrrFrom nuclear structure to particle transfer reactions and back (ECT*) TrentoItalie (2013-11-04)
Alpha cluster structure in 56NiH. Akimune et al.J. Physics: Conf. Series 436 (2013) 01201010th Int. Conf. Clustering Aspects of Nuclear Structure and DynamicsDebrecen Hongrie (2012-09-24)
Breakup Reactions of Drip-Line Nuclei Near N = 20, 28N. Kobayashi et al.Few-Body Systems 54 (2013) 1441-144420th Int. IUPAP Conf. Few-Body Problems in Physics Fukuoka Japon (2012-08-20)
Scattering of 8He on 208Pb at 22 MeVG. Marquínez-Durán et al.AIP Conference Proceedings 1541 (2013) 175-176 Int. Scientific Meeting on Nuclear Physics Basic Concepts in NuclearPhysics: Theory, Experiments, and Applications La RabidaEspagne (2012-09-09)
Invariant Mass Spectroscopy of O-23 via the (p, p') Reaction in Inverse KinematicsY. Satou et al.Few-body Systems 54 (2013) 54 287-290 5th Asia-Pacific Conf. Few-Body Problems in Physics 2011 (APFB2011) Seoul, République De Corée (2011-08-22)
The N=16 Spherical Shell Closure in O-24K. Tshoo et al.Few-body Systems 54 (2013) 459-463 5th Asia-Pacific Conf. Few-Body Problems in Physics 2011 (APFB2011) Seoul, République De Corée (2011-08-22)
Elastic scatterring of the 8He + 208PB at 22 MeVG. Marquínez-Durán et al.Acta Physica Polonica B 44 (2013) 467-470 Zakopane Conf. Nuclear Physics "Extremes of the Nuclear Landscape" Zakopane Pologne (2012-08-27)
Study of neutron rich nucleus 25F via single-step fragmentationZ. Vajta et al.Acta Physica Polonica B 44 (2013) 553-557 Zakopane Conf. Nuclear Physics "Extremes of the Nuclear Landscape" Zakopane Pologne (2012-08-27)
Direct radiative proton capture 23Al(p,α)24Si studied via one-proton nuclear breakup of 24SiA. Banu et al.J. Physics: Conference Series 337 (2012) 012059 Nuclear Physics in Astrophysics V Eilat, Israël (2011-04-03)
Astrophysical(α,γ) reaction in inverse kinematics; Electron screening effect in thebeta-decayP. Ujic et al.J. Physics: Conference Series 337 (2012) 012015Nuclear Physics in Astrophysics V Eilat, Israël (2011-04-03)
Scattering of 8He on 208Pb at Energies Around the Coulomb BarrierG. Marquínez-Durán et al.Acta Physica Polonica B 43 (2012) 239-245 XXXII Mazurian Lakes Conf. Physics Piaski Pologne (2011-09-11)
Resonances in 19Ne with relevance to the astrophysicallyimportant 18F(p,α)15O reactionD. Mountford et al.PoS - Proceedings of Science (2012) ENAS 6 050 VIEuropean Summer School on Experimental Nuclear AstrophysicsAcireale, Italie (2011-09-18)
A new neutron time of flight array for beta-decay studiesF. DelaunayISOLDE Workshop and Users Meeting Geneve, Suisse (2013-11-25)
Development of a new neutron time-of-flight array for beta-decaystudiesF. DelaunayUniversidad de Santiago de Compostela Santiago de Compostela, Espagne (2013-04-04)
A Neutron Time-of-Flight Array for SPIRAL2-DESIRF. DelaunayNEDENSAA NuPNET Collaboration Meeting 2013 Acireale, Italie (2013-02-20)
Towards beta-delayed neutron decay studies at DESIR-SPIRAL2F. DelaunayXVIII Colloque GANIL Port-en-Bessin, France (2013-09-23)
Structure of unbound neutron-rich 9He studied using the single-neutron transferJ. GibelinXVIII Colloque GANIL Port-en-Bessin, France (2013-09-23)
Exploring the structure of the most neutron-rich isotopes of Boron and CarbonF.M. MarquesFrench-Japanese Symposium on Nuclear Structure Problems Paris, France (2013-09-30)
86
Correlations at the limits of nuclear existenceF.M. MarquesIX Workshop on Correlation and Femtoscopy - WPCF2013 Acireal, Italie 2013-11-05
Around and beyond the neutron dripline for ZF.M. MarquésESNT Workshop on Localization and clustering in atomic nuclei Saclay, France (2013-05-30)
Evolution of the shell structure in medium-mass nuclei : search for the 2d5/2 neutronorbital in 69NiM. Moukaddam et al.Shell Model as a Unified View of Nuclear Structure Strasbourg, France (2012-10-08)
Progress towards a new neutron time-of-flight arrayF. DelaunayCSIC-IEM Madrid, Espagne (2012-02-1)
Nuclear dynamics and thermodynamicsThe behaviour of constrained caloric curves as ultimate signature of a phase transition for hot nucleiB. Borderie et al.NN2012 Proceedings 420 (2013) 012081 11th Int. Conf. Nucleus-Nucleus Collisions (NN2012) San Antonio, Texas, États-Unis
Long lifetime components in the decay of excited super-heavy nucleiM. Morjean et al.EPJ Web of Conferences 63 (2013) 02011 2nd Heavy Ion Accelerator Symposium for Fundamental and Applied Research (HIAS) Canberra, Australie (2013-04-08)
Influence of neutron enrichment on compound system formation and decay in 78Kr+40Ca and 86Kr+48Ca reactions at 10 AMeVS. Pirrone et al.AIP Conference Proceedings 1524 (2013) 7-10Int. Conf. Recent Trends in Nuclear Physics Barotiwala, Inde(2012-11-19)
Search for α-particle condensation in nuclei from the Hoyle state deexcitationA. Raduta et al.J. Physics: Conference Series 420 (2013) 01208711th Int. Conf. Nucleus-Nucleus Collisions (NN2012) San Antonio,Texas, États-Unis (2012-05-27)
Status and performances of the FAZIA projectM.F. Rivet et al.FAZIAJ. Physics: Conference Series 420 (2013) 012160 11th Int. Conf. Nucleus-Nucleus Collisions (NN2012) San Antonio,Texas, États-Unis (2012-05-27)
Effects of irradiation of energetic heavy ions on digital pulse shapeanalysis with silicon detectorsS. Barlini et al.FAZIAProceedings of the 13th Int. Conf. Nuclear Reaction Mechanisms(2012) 415-419, Varenna Italie (2012-06-11)
The Fazia initiative: more powerful detectors for a more detailedinvestigation on the origin and the decay of charged fragments G. Casini et al.FAZIAProceedings of the 13th Int. Conf. Nuclear Reaction Mechanisms(2012) 407-414, Varenna Italie (2012-06-11)
Recent results from INDRAJ.D. Frankland et al.EPJ Web of Conferences 31 (2012) 00002 Int. Workshop Multifragmentation and Related Topics - IWM2011 Caen, France (2011-11-02)
Chemistry of nuclear particle production in 32 A MeV 136,124Xe+124,112Sn reactionsand nuclear symmetry energyM. Kabtoul et al.INDRAEPJ Web of Conf. 31 (2012) 00010 Int. Workshop Multifragmentation and related topics - IWM 2011 Caen, France (2011-11-02)
Decay modes of the systems formed in the reactions 78Kr+40Ca and 86Kr+48CaM. La Commara et al.EPJ Web of Conf. 31 (2012) 00022 Int. Workshop Multifragmentation and related topics - IWM 2011 Caen, France (2011-11-02)
Characterization of quasi-projectiles produced in symmetriccollisions studied with INDRA comparison with modelsE. Legouée et al.EPJ Web of Conf. 31(2012) 00007 Int. Workshop Multifragmentation and related topics - IWM 2011 Caen, France (2011-11-02)
Nuclear symmetry energy in calcium-calcium collisionsP.C. Wigg et al.EPJ Web of Conf. 31 (2012) 00015 Int. Workshop Multifragmentation and related topics - IWM 2011 Caen, France (2011-11-02)
Direct evidence of #-particle condensation for the Hoyle stateA. Raduta et al.ISOSPINEPJ Web of Conf. 31(2012) 00034 Int. Workshop Multifragmentation and related topics - IWM 2011 Caen, France (2011-11-02)
Asymmetric fission in 78Kr+40Ca reactions at 5.5 MeV/nucleonJ.P. Wieleczko et al.EPJ Web of Conf. 21 (2012) 02001 Third International Workshop on Compound3rd Int. Workshop Compound Nuclear Reactions and Related Topics(CNR11) Prague, République Tchèque (2011-09-19)
Study and comparison of the decay modes of the systems formedin the reactions 78Kr+40Ca and 86Kr+48Ca at 10 AMeVS. Pirrone et al.EPJ Web of Conf. 21 (2012) 02003 3rd Int. Workshop Compound Nuclear Reactions and Related Topics(CNR11) Prague, République Tchèque (2011-09-19)
87
The european FAZIA initiative: a high-performance digital telescope array for heavy-ion studiesG. Casini et al.FAZIA (2013) 25th Int. Nuclear Physics Conf. (INPC 2013) Firenze, Italie (2013-06-02)
Status of the Fazia projectN. Le NeindreSPES One Day Workshop Isospin on reaction mechanism with RIBs'Catania, Italie (2013-10-08)
Nuclear stopping for heavy ions induced reactions in the Fermi energy range: from 1-body to 2-body dissipationO. LopezInt. Nuclear Physics Conf. INPC2013 Firenze Italie (2013-06-02)
Large area diamond detector as heavy ion beam profilersM. PârlogHIE ISOLDE Workshop : the technical aspect Geneve, Suisse (2013-11-28)
Theoretical physics and phenomenologySome aspects of the phase diagram of nuclear matter relevant to compact starsF. Gulminelli et al.J. Physics: Conference Series 413 (2013) 012019 Int. Summer School for Advanced Studies 'Dynamics of open nuclearsystems' (PREDEAL12) Predeal, Roumanie(2012-07-09)
Neutron-rich nuclei and the equation of state of stellar matterF. GulminelliPhysica Scripta (2013) 014009 Nobel Symposium NS 152: Physics with Radioactive Beams Gothenburg, Suède (2012-06-10)
Phase diagram of neutron-rich nuclear matter and its impact on astrophysicsF. Gulminelli et al.J. Physics: Conference Series 420 (2013) 012079 11th International Conference on Nucleus-Nucleus Collisions (NN2012) San Antonio, (Texas) États-Unis (2012-05-27)
Statistical (?) decay of light hot nucleiG. Baiocco et al.EPJ Web of Conf. 31 (2012) 00038 Int. Workshop Multifragmentation and related topics - IWM 2011 Caen, France (2011-11-02)
An interpretation of staggering effects by correlation observablesM. D'Agostino et al.EPJ Web of Conf. 31 (2012) 00008 Int. Workshop Multifragmentation and related topics - IWM 2011 Caen, France (2011-11-02)
Fragmentation and clustering in star matterF. GulminelliEPJ Web of Conf. 31 (2012) 00018 Int. Workshop Multifragmentation and related topics - IWM 2011 Caen, France (2011-11-02)
Staggering in S+Ni collisionsL. Morelli et al.EPJ Web Conf. 31 (2012) 0042International Workshop on Multifragmentation and Related Topics -IWM 2011, Caen, France (2011)
Scattering of 8He on 208Pb at Energies Around the Coulomb BarrierG. Marquínez-Durán et al.Acta Physica Polonica B 43 (2012) 239-245 XXXII Mazurian Lakes Conf. on Physics Piaski, Pologne (2011-09-11)
Surface properties of nuclei embedded by a nucleon gas in the framework of the extended Thomas-Fermi theoryF. Aymard et al.Journées de Rencontres Jeunes Chercheurs 2013 Barbaste, France (2013-12-01)
EOS of neutron-rich nuclear matter and its impact on astrophysicsF. Gulminelli4th Int. Conf. Nuclear Fragmentation - NUFRA2013 Kemer, Turquie(2013-09-29)
Similarities and differences between two aspects of nuclear clustering: stellar matter and nuclear fragmentationF. GulminelliESNT Workshop on Localization and clustering in atomic nuclei Saclay, France (2013-05-30)
Clusters in hot and dense stellar matterF. Gulminelli41st Int. Workshop on Gross Properties of Nuclei and Nuclear Excitations Hirschegg, Autriche (2013-01-26)
Phase diagram of nuclear matter and its impact on astrophysicsF. GulminelliNuclear Equation of State for Compact Stars and Supernovae Francfort, Allemagne (2012-11-28)
A phase-free quantum Monte Carlo method for the nuclear shell modelJ. Bonnard2nd European Nuclear Physics Conference Bucarest, Roumanie (2012-09-17)
Nuclear waste managementOperation of the accelerator driving the VENUS-F core for the low power ADSexperiments Guinevere and FREYA at SCK-CENM. Baylac et al.Proc. of 2nd Int. Workshop on Technology and Components of Accelerator-driven Systems (TCADS-2) Nantes, France (2013-05-21)
FALSTAFF: A new tool for fission studiesD. Dore et al.EPJ Web of Conf. 62 (2013) 050055th Int. Workshop on Nuclear Fission and Fission-Product SpectroscopyCaen, France (2013-05-28)
Fission Fragment characterization with FALSTAFF at NFSD. Doré et al.FALSTAFF; NFSEPJ Web of Conf. 42 (2013) 1001 WONDER-2012 - 3rd Int. Workshop On Nuclear Data Evaluation for Reactor applications Aix-en-Provence, France (2012-09-25)
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The GUINEVERE Experiment: first PNS measurements in a lead moderated sub-critical fast coreH.E. Thyebault et al.GUINEVEREInt. Congress on the Advances in Nuclear Power Plants (ICAPP'12) Chicago, États-Unis (2012-06-24)
Detector positioning for the initial subcriticality leveldetermination in Accelerator-DrivenSystemsW. Uyttenhove et al.Physics in Reactors Topical Meeting (PHYSOR 2012) Knoxville, États-Unis (2012-04-15)
FALSTAFF: a novel apparatus for fission fragment characterizationS. Panebianco et al.4th Int. Workshop on Compound-Nuclear Reactions and Related Topics(CNR13) Maresias, Brésil (2013-10-07)
Operation of the GENEPI-3C accelerator for the ADS mock-up GUINEVEREE. Froidefond et al.11th International Topical Meeting on Nuclear Applications ofAccelerators (AccApp2013) Bruges, Belgique (2103-08-05)
FALSTAFF : a New Tool for Fission Fragment CharacterizationD. Dore et al.International Conference on Nuclear Data for Science and Technology(ND2013) New York, États-Unis (2013-03-04)
The Neutrons For Science facility at SPIRAL-2X. Ledoux et al.International Conference on Nuclear Data for Science and Technology(ND2013) New York, États-Unis (2013-03-04)
Double Differential Cross Sections for Light-Ion Production fromC, O, Si, Fe and BiInduced by 175 MeV Quasi-Monoenergetic NeutronsR. Bevilacqua et al.International Conference on Nuclear Data for Science and Technology(ND2013) New York, États-Unis (2013-03-04)
Analysis of prompt decay experiments for ADS reactivitymonitoring at VENUS-F GUINEVERE facilityS. Chabod et al.Int. Workshop on Technology and Components of Accelerator Driven Systems (TCADS-2) OECD NuclearEnergy Agency Nantes, France (2013-05-21)
Current progress and future plans of the FREYA ProjectA. Kochetkov et al.Int. Workshop on Technology and Components of Accelerator DrivenSystems (TCADS-2) OECD NuclearEnergy Agency Nantes, France (2013-05-21)
Reactivity monitoring using the area method for the subcriticalVENUS-F core within theframework of the FREYA ProjectN. Marie et al.Int. Workshop on Technology and Components of Accelerator DrivenSystems (TCADS-2) OECD NuclearEnergy Agency Nantes, France (2013-05-21)
An alternative source Jerk method implementation for the subcriticality estimation of theVenus-F subcritical core in the FREYA projectA. Kochetkov et al.ANIMMA 2013 - Avancements in Nuclear Instrumentation Measurement Methods and their applications Marseille, France (2013-06-23)
FALSTAFF: a novel setup for actinide fission fragment characterization at NFS(SPIRAL2)F.R. LecolleyXVIII Colloque GANIL Port-en-Bessin, France (2013-09-23)
FALSTAFF: a new setup for fission fragment and neutron multiplicity characterizationF.R. Lecolley11th International Topical Meeting on Nuclear Applications of Accelerators Bruges, Belgique (2013-08-05)
Medical and industrialapplicationsFIRST experiment: Fragmentation of Ions Relevant for Space and TherapyC. Agodi et al.Journal of Physics: Conference Series 420 (2013) 012061 11th International Conference on Nucleus-Nucleus Collisions (NN2012) San Antonio, (Texas) États-Unis (2012-05-27)
Comparisons of hadrontherapy-relevant data to nuclearinteraction codes in the Geant4 ToolkitB. Braunn et al.Journal of Physics: Conference Series 420 (2013) 012163 11th International Conference on Nucleus-Nucleus Collisions (NN2012) San Antonio, (Texas) États-Unis (2012-05-27)
95MeV/u 12C nuclear fragmentation measurements on thin targetsfor hadrontherapyJ. Colin et al.13th Int. Conf. Nuclear Reaction Mechanisms Varenna, Italie (2012-06-11) (Proc. (2012) 459-460
The FIRST experiment for nuclear fragmentation measurements at GSIB. Golosio et al.Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2011 Valencia, Espagne (2011-10-23) (Proc. (2012) 2277-2280)
95MEV/U 12C Nuclear fragmentation measurements for hadrontherapy purposesM. Labalme et al.Radiotherapy and Oncology 102 (2012) S69 ICTR-PHE 2012 Conference Genève, Suisse (2012-02-27)
Nuclear Fragmentation Measurements for Hadrontherapy: 95MeV/u 12C Reactions on H, C, Al, O and natTi TargetsJ. Dudouet et al.International Conference on Nuclear Data for Science and Technology(ND2013) New York, États-Unis (2013-03-04)
Carbon fragmentation measurements at 95MeV and comparisonswith GEANT4 simulations for hadrontherapyJ. DudouetXVIII Colloque GANIL Port-en-Bessin, France 2013-09-23
The "PTFI", a beam profiler for low intensity, low energy radioactive beam measurementsJ.M. FontbonneHIE ISOLDE Workshop : the technical aspect Geneve, Suisse (2013-11-28)
89
Neutrino and fundamentalinteractionsFirst measurement of a pure electron shake-off in beta decay of trapped 6He+ ionsX. FléchardJoint Symposium on Collision Processes of Highly-Charged Ions and Related Topics Tokyo, Japon (2012-02-03)
Development of target ion source systems for radioactive beams at GANILO. Bajeat et al.SPIRAL2NIM B 317 (2013) 411-416 16th Int. Conf. Electromagnetic Isotope Separators and Technique related to their Applications (EMIS2012) Matsue, Japon (2012-12-02)
Weak Interaction Studies with 6HeKnecht A. et al.AIP Conference Proceedings 1560 (2013) 63611th Conf. intersections of particle and nuclear physics (CIPANP 2012), St Petersburg, États-Unis (2012-05-29)
In gas laser ionization and spectroscopy experiments at the Superconducting SeparatorSpectrometer (S3): Conceptual studies and preliminary designR. Ferrer et al.NIM B 317 (2013) 570-581 16th Int. Conf. Electromagnetic Isotope Separators and Technique related to their Applications (EMIS2012) Matsue, Japon (2012-12-02)
Measurement of the 6Li charge state distributions following the 6He+ beta decayC. Couratin et al.J. Physics: Conference Series 388 (2012) 152013 XXVII International Conference on Photonic, Electronic andAtomic Collisions (ICPEAC 2011) Related topics Belfast, Irlande (2011-07-27)
Study of low energy ion-atom collisions using a magneto-opticaltrapA. LereddeJ. Physics: Conference Series 388 (2012) 082005XXVII International Conference on Photonic, Electronic andAtomic Collisions (ICPEAC 2011) Related topics Belfast, Irlande (2011-07-27)
Prospects for advanced electron cyclotron resonance and electronbeam ion source charge breeding methods for EURISOLP. Delahaye et al.Review of Scientific Instruments 83 (2012) 02A906 14th International Conference on Ion Sources - ICIS 2011Giardini Naxos, Italie (2011-09-12)
Status of the SPIRAL I upgrade at GANILP. Jardin et al.Review of Scientific Instruments 83 (2012) 02A91114th International Conference on Ion Sources - ICIS 2011Giardini Naxos, Italie (2011-09-12)
Precision measurements in nuclear beta-decay with LPCTrapX. Fléchard10th Latin American Symposium on Nuclear Physics and Applications Montevideo, Uruguay (2013-12-01)
Upgrade SPIRAL1: vers une extension de la gamme des faisceaux d'ions radioactifs à GANILM. Dubois et al.SPIRALLes Journées Accélérateurs de la SFP Roscoff, France (2013-10-14)
A radio-frequency cooler (RFQ Cooler) for high intensityradioactive beams at DESIRJ.F. CamXVIII Colloque GANIL Port-en-Bessin, France (2013-09-23)
Simultaneous measurement of the β−ν correlation coefficient αβνand "shake-off“ probability in the β decay of noble gas 1+ ionsX. FabianXVIII Colloque GANIL Port-en-Bessin, France (2013-09-23)
Fundamental interaction reviewE. LienardXVIII Colloque GANIL Port-en-Bessin, France (2013-09-23)
Continuous wave formation of highly charged EBIS beams at ISOL facilitiesE. Traykov et al.EURORIB 2012 - European Radioactive Ion Beam Conference. Padova, Italie (2012-05-20)
High intensity radioactive beam cooling for SPIRAL II/DESIRG. BanInt. Symposium on Exotic Nuclei Vladivostok, Fédération De Russie (2012-10-01)
Beta-neutrino correlation measurements with radioactive ions in trapsG. BanInt. Symposium on Exotic Nuclei Vladivostok, Fédération De Russie (2012-10-01)
RFQ Cooler experimental resultsR. BoussaïdSPIRAL2 Week 2012 Caen, France (2012-01-23)
Searches for neutrinoless double beta decayF. MaugerNeutrinos at the forefront of elementary particle physics and astrophysics Lyon, France (2012-10-22)
Electronics and microelectronicsFront-end electronics for the SuperB charged particle identification detectorsC. Beigbeder et al.NIM A 718 (2013) 186-188 12th Pisa Meeting on Advanced Detectors La Biodola, Italie (2012-05-20)
Schedules and WBS: why and howP. LaborieSPIRAL2 Week 2012 Caen, France (2012-01-23)
90
Personnels permanents
Organigramme
Chercheurs associés
Glossaire
INFORMATIONS GÉNÉRALES
91
PERSONNELS PERMANENTS
Ingénieurs, Techniciens et Administratifs
BOUGARD Bruno T UCBN
BOUMARD Frédéric IE CNRS
BREGEAULT Joël IE UNIV
CAM Jean-François AI CNRS
CARNIOL Benjamin IE CNRS
CAUVIN Alain IE CNRS CDD
CHAVENTRE Thierry IE CNRS
DESRUES Philippe AI CNRS
DEVAUX Véronique T CNRS
DROUET Sébastien IR CNRS
ETASSE David IR CNRS
FONTBONNE Cathy IR CNRS
FONTBONNE Jean-Marc IR CNRS
FRANCK de PREAUMONT Hugues IE CNRS
GABRIEL Jean-Louis AI CNRS
GONTIER Aurélie T CNRS
GOUPILLIERE Damien IE UNIV
GUESNON Olivier T CNRS
GUESNON Sandrine AI CNRS
HARANG Julien T UNIV
HOMMET Jean IE CNRS
KERMORVANT Yoann T UCBN
LABORIE Philippe IR CNRS
LANCIEN Lydie ADJ UNIV
LANGLOIS Jérôme AI CNRS
LAUNAY Thierry IE CNRS
LECONTE Albert IR CNRS
LETERRIER Laurent IR CNRS
LORY Julien AI CNRS
MERRER Yvan IR CNRS
NOBLET Laurent T CNRS
PAIN Cédric AGT UNIV
PERRONNEL Jérôme AI CNRS
POINCHEVAL Jérôme AI UNIV
VANDAMME Christophe AI CNRS
ZWOLINSKI David IE CNRS
Chercheurs et Enseignants-Chercheurs
ACHOURI Lynda CR CNRS
ANGELIQUE Jean-Claude PROF ENSI
BAN Gilles PROF ENSI
BOUGAULT Rémi DR CNRS
COLIN Jean PROF UNIV
CUSSOL Daniel CR CNRS
DELAUNAY Franck MC IUT UNIV
DURAND Dominique DR CNRS
FLECHARD Xavier CR CNRS
GIBELIN Julien MC UNIV
GUILLON Benoît MC ENSI
GULMINELLI Francesca* PROF UNIV
JUILLET Olivier PROF UNIV
LABALME Marc MC ENSI
LECOLLEY François-René MC UNIV
LECOUEY Jean-Luc MC ENSI
LEFORT Thomas MC UNIV
LEHAUT Grégory CR CNRS
LEMIERE Yves MC UNIV
LE NEINDRE Nicolas CR CNRS
LIENARD Etienne MC UNIV
LOPEZ Olivier CR CNRS
MARIE-NOURRY Nathalie MC UNIV
MARQUES Miguel CR CNRS
MAUGER François PROF UNIV
NAVILIAT Oscar PROF UNIV DET
ORR Nigel CR CNRS
PARLOG Marian CDI CNRS
QUEMENER Gilles CR CNRS
SALVADOR Samuel CR CNRS
VIENT Emmanuel MC UNIV
Doctorants
AUGEY Lou FABIAN Xavier
AYMARD François HELAINE Victor
BOISSONNAT Guillaume LEBLOND Sylvain
DUDOUET Jérémie LEPREVOST Alexandre
CHEVREY Thibault PEREIRA-LOPEZ JesusEmérites
GUERREAU Daniel DR CNRS
LECOLLEY Jean-François PROF UNIV
PETER Jean DR CNRS
TAMAIN Bernard PROF ENSI * Membres de l’Institut Universitaire de France
92
ORGANIGRAMME
DÉCEMBRE 2013
93
2012RADUTA Adriana 26/03/2012 au 26/05/2012
12/11/2012 au 16/11/2012
BAIOCCO Giorgio 12/09/2013 au 04/12/2012
ZEJMA Jacek 12/11/2012 au 14/11/2012
BODEK Kaziemierz 12/11/2012 au 14/11/2012
ZENNER Johannes 12/11/2012 au 14/11/2012
KHOMUTOV Nicolay 12/11/2012 au 14/11/2012
DOMINGUEZ Beatrix 06/12/2012 au 18/12/2012
2013RADUTA Adriana 04/03/2013 au 05/04/2013
06/10/2013 au 08/11/2013
WYSZYNSKI Grzegorz 03/04/20013 au 12/04/2013
AL FALOU Hicham 01/07/2013 au 31/07/2013
POROBIC Tomica 21/10/2013 au 15/11/2013
FINLAY Paul 21/10/2013 au 15/11/2013
ZEJMA Jacek 05/11/2013 au 08/11/2013
LAUSS Berhnard 05/11/2013 au 08/11/2013
CHERCHEURS ASSOCIÉS
94
GLOSSAIRE
ACMO: Agent in charge of the Implementation of health and safety.ADS: Accelerator Driven SystemANR: Agence Nationale pour la RechercheARCHADE : Advanced Resource Centre for Hadrontherapyin EuropeASIC: Application Specific Integrated CircuitsASN: Autotité de Sûreté NucléaireCAO: Conception Assistée par OrdinateurCEA: Commissariat à l’Energie AtomiqueCIMAP: Centre de Recherche sur les Ions, les matériaux et la photoniqueCMOS: Complementary Metal Oxide SemiconductorCNRS: Centre National de la Recherche ScientifiqueCSNSM: Centre de Spectrométrie Nucléaire et de Spectrométrie de MasseDEMON: DEtecteur MOdulaire de NeutronsDESIR: Désintégration, Excitation et Stockage d’Ions RadioactifsDOSION: on-Line Beam Monitoring for HadronbiologyEDMS: Engineering Data Management SystemEMILIE: Enhanced Multi-Ionisation of short-Lived Isotopes at EurisolENSICAEN: Ecole Nationale Supérieure d’Ingénieurs de CAENEURISOL: EURopean Isotope Separation On Line (6e PCRD)FASTER: Système d’acquisition de données numériquesFAZIA: Four π A and Z Identification ArrayFPGA: Field-Programmable Gate ArrayGANDALF: Système for highly interactive software development environmentsGANIL: Grand Accélérateur National d’Ions LourdsGDR: Groupement de RechercheGEANT 4: outil de simulation de l'interaction entre matière et particulesGEM: Gas Electron MultiplierGENEPI-3C: Générateur de Neutrons Pulsé Intense ContinuGESLAB: Logiciel de gestion des laboratoires CNRSGSI : Centre Helmholtz pour la recherche Heavy Ion GmbHGUINEVERE: Generator of Uninterrupted Intense NEutronsat the lead VEnus Reactor
HAL: Hyper Articles en Ligne (Open Access archives)IAO: Ingénierie Assistée par OrdinateurIBE: Energy Beam IdentificationINDRA: Identification de Noyaux et Détection avec Résolution AccrueIN2P3: Institut National de Physique Nucléaire et de Physique des ParticulesIPHC: Institut Pluridisciplinaire Hubert CurienIPNL : Institut de Physique Nucléaire de LyonITA : Ingénieurs, Techniciens et AdministratifsIRFU: Institut de Recherche sur les lois Fondamentales de l’Univers (CEA)IRSN: Institut de Radioprotection et de Sûreté NucléaireLIRAT : Ligne d’Ions Radioactifs à Très basse énergieLISE : Ligne d’Ions Super EpluchésLPC : Laboratoire de Physique CorpusculaireMCNP : Monte Carlo N ParticlesMESR: Ministère de l’Enseignement Supérieur et de la RechercheMOT : Magneto Optical TrapMUSE : MUltiplication Source ExterneNEBULA: Large area neutron arrayNEMO : NEutrino MolybdènePCR: Person Competent in Radiation protectionPEEK: Polyether Ether KetonePIPERADE: Piège de Penning pour des ions Radioactifs à DEsirPSI : Paul Scherrer InstituteRFQ : Radio Frequency QuadrupoleROOT : An objet oriented data analysis frameworkSHIRAC : Spiral2 High Intensity RAdiofrequency CoolerSIFAC: Système d’Information Financier et Analytique et Comptable des universités.SPIRAL : Linear Particle Accelerator Project at GANILTONNERRE : TONneau pour NEutRons REtardésTPS : Treatment Planning SystemUCBN : Caen Basse-Normandy UniversityUCN : Ultra Cold NeutronsVENUS : Vulcain Experimental NUclear Study
95
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