The PRISMA spectrometer : Status and The PRISMA spectrometer : Status and P ti P ti Perspectives Perspectives

L CorradiL.Corradi for the PRISMA collaboration

Laboratori Nazionali di Legnaro – INFN, Italy

SPES2014, Legnaro, May 26-28, 2014

PRISMA PRISMA PRISMA : PRISMA : the system and its the system and its

l f l f general performance general performance

THETHE PRISMAPRISMA SPECTROMETERSPECTROMETER coupledcoupled totoCLARACLARA andand AGATAAGATA DEMONSTRATORDEMONSTRATOR GAMMAGAMMA ARRAYARRAY

PRISMA: a large acceptance magnetic spectrometer

INFN exp. PRISMA (LNL,PD,TO,Na)

INFN GAMMA (LNL PD Fi MI N P ) magnetic spectrometer Ω ≈ 80 msr; Bρmax = 1.2 TmΔA/A ~ 1/200Energy acceptance ~ ±20%

INFN exp. GAMMA (LNL,PD,Fi,MI,Na,Pg)

+ broad Int. Collaboration (UK,F,D,Pl,Sp,Ro,Hr)

MCP

PRISMAPRISMA spectrometerspectrometer –– aa complexcomplex detectordetector systemsystem

PPAC

IC∆E

64Ni+238U

E

PRISMAPRISMA spectrometerspectrometer –– trajectorytrajectory reconstructionreconstruction

MWPPAC

AA physicalphysical eventevent isis composedcomposed byby thethe parametersparameters::•• positionposition atat thethe entranceentrance x,x, yy•• positionposition atat thethe focalfocal planeplane X,X, YYpp pp ,,•• timetime ofof flightflight TOFTOF•• energyenergy DE,DE, EE

∆∆EE –– EE matrixmatrix inin 8282Se+Se+238238UU atat EElablab==505505 MeV,MeV, θθlablab == 6464oo

fission events

PRISMA

fission eventsZ=50

]

proton pick-up channels

rb. U

nits

Z=34

∆E

[ar

proton stripping channelsproton stripping channels

beam current 2 pnAacquisition time 1 hour

Energy [arb. units]

PRISMAPRISMA spectrometerspectrometer –– trajectorytrajectory reconstructionreconstruction

∆E-E

Mass

A/q

q

S.Szilner et al, Phys.Rev.C76(2007)024604

L.Corradi et al., J.Phys.G36(2009)113101

CrossCross sectionsection measurementsmeasurements inin 8282Se+Se+238238UU atat EElablab==505505 MeVMeV

88Se

82GeGe

80Zn

74NiCross sections for exotic nuclei like the

N=50 82Ge or 80Zn could be mesaured down to few μb level

Ni

The physics cases The physics cases The physics cases The physics cases

REACTION MECHANISMS

● near barrier multinucleon transfer ● sub-barrier transfer (pair correlations)(p )

elastic, inelastic scatteringproduction of neutron rich heavy partner

GAMMA SPECTROSCOPY

● lifetime measurements ● spectroscopy of neutron rich nuclei (light and heavy)● spectroscopy of neutron rich nuclei (light and heavy)

properties of electromagnetic transitions (spin alignment)spectroscopy of fission products

MultineutronMultineutron andand multiprotonmultiproton transfertransfer channelschannels nearnear closedclosed--shellshell nucleinuclei

experimental total cross sections compared with GRAZING code calculations

Mass [amu]at near barrier energies

angular distributions are bell shaped and with a singlebell shaped and with a single setting of the spectrometer one gets most of the total

transfer flux

S.Szilner et al, Phys.Rev.C76(2007)024604

Multineutron and multiproton transfer using Multineutron and multiproton transfer using neutron rich radioactive beamsneutron rich radioactive beams

the (being) studied reactions are also a

benckmark for reactionsbenckmark for reactions with unstable beams

via mnt one predicts highvia mnt one predicts high production cross

sections for very neutron rich medium mass nucleirich medium mass nuclei

GRAZING code calculations - G.Pollarolo

PRISMAPRISMA simulationssimulations ofof ionion transporttransport

Correction factors derived from bidimensional E-θ uniform input distributions

4848Ca+Ca+6464NiNi E=E=270270 MeVMeV

D.Montanari et al, EPJA(2011)47

MeasurementsMeasurements ofof differentialdifferential crosscross sectionssections

experimental differential cross sections for one particle transfers compared with GRAZING code calculations

4848Ca+Ca+6464NiNi EElablab==66 MeV/AMeV/A4040Ar+Ar+208208PbPb EElablab==66..44 MeV/AMeV/A

41Ar

T.Mijatovic et al, AIP Conf. Vol.1491(2012),346

D.Montanari et al, Phys.Rev.C84(2011)054613

combiningcombining yieldsyields withwith andand withoutwithout gammagamma coincidencescoincidences

9090 208208Pb l Pb l 4848 6464N l N l 9090Zr+Zr+208208Pb elastic scattering Pb elastic scattering 4848Ca+Ca+6464Ni inelastic scattering Ni inelastic scattering

D.Montanari et al, PRC84(2011)054613 S.Szilner et al, Phys.Rev.C76(2007)024604

96

DetectionDetection ofof (light)(light) targettarget likelike ionsions inin inverseinverse kinematicskinematics withwith PRISMAPRISMA

C di l PRC84(2011)03460340

beam direction

20o

96Zr L.Corradi et al, PRC84(2011)034603 40Ca

20o

116Sn 60Ni D.Montanari et al, INPC2013 Prisma acceptance

54Fe

MNT channels have been measured down to 25 % below the Coulomb barrier

92Mo S.Szilner et al, exp March 2013

Eca ~ 5 MeV/AE > EB

E < EB

E << EB

ComparisonComparison betweenbetween experimentalexperimental andand theoreticaltheoreticaltransfertransfer probabilitiesprobabilitiestransfertransfer probabilitiesprobabilities

microscopic calculations based on semiclassical

theory

importance of high energy 0+ states and of states of different

multipolarity

L.Corradi, S.Szilner, G.Pollarolo et al, PRC84(2011)034603

THETHE PRISMAPRISMA ++ CLARA/AGATACLARA/AGATA CAMPAIGNCAMPAIGN

Grazing reactions as a tool to study nGrazing reactions as a tool to study n--rich nucleirich nuclei

- evolution of shell structures- lifetime measurements - strength functions- polarization effects in mnt

136Xe136Xe

To do that we used the most neutron rich

82Se82Se70Zn70Zn64Ni64Ni

96Zr96Zr

To do that we used the most neutron-richstable beams available at the Tandem/PIAVE-ALPI accelerator complex of LNL at energies5-15% above the Coulomb barrier

36S36S26Mg26Mg

22Ne22Ne

48Ca48Ca40Ar40Ar

17

5 15% above the Coulomb barrier

LifetimesLifetimes measurementsmeasurements inin 4848Ca+Ca+208208PbPb atat EElablab==310310 MeVMeV

DifferentialDifferential PlungerPlunger MethodMethod

comparison of pdeduced

B(E2) with large scale shell model calculations

J.J.Valiente-Dobon et al, PRL102(2009)242502

Spectroscopy of neutron rich Fe isotopes produced in the Spectroscopy of neutron rich Fe isotopes produced in the 6464Ni+Ni+238238U U multinucleon transfer reactionsmultinucleon transfer reactions

GOAL: to explore th evolution of the known shell closure for large N/Z ratio

and to characterize new regions of deformationsdeformations

S.Lunardi et al., Phys. Rev. C 76(2007)034303

Spectroscopy on neutron rich nuclei produced in Spectroscopy on neutron rich nuclei produced in 4040Ar+Ar+208208Pb and Pb and 7070Zn+Zn+238238U multinucleon transfer reactionsU multinucleon transfer reactions

CoAr with the good mass identification and high

detection efficiencydetection efficiency, spectroscopy could be

performed in large isotopic chains

interplay between single parttcle

toward the N=40 subshell closure, shell model description of spherical

and deformed statesinterplay between single-parttcle and collective excitations in Ar

isotopes

and deformed states

Co isotopes

Ar isotopes

S.Szilner et al, PRC84(2011)014325 F.Recchia et al, PRC85(2012)064305

SpinSpin alignmentalignment inin 4848Ca+Ca+6464NiNi andand 4848Ca+Ca+208208PbPb mntmnt reactionsreactions

mnt reactions produce a large degree of spin alignment, which allows to study decay properties of populated states

positive parity states obtained within the particle-vibration model employing

S Sfraction of full spin alignment

the SkX Skyrme interaction

D.Montanari et al, PLB697(2011)288 and PRC85(2012)044301

NeutronNeutron richrich nucleinuclei producedproduced inin thethe fissionfission ofof 238238UU inin136136Xe+Xe+238238UU atat EElablab==990990 MeVMeV

Part of the detected yield should correspond to transfer induced fission, a mechanism suitable to produce more neutron rich nuclei

PRISMA setted in order to detect ( ) f(lighter) fission

fragments

Extended the studies of the evolution of

collectivity in n-rich Kr isotopes

N.Marginean et al., Phys. Rev. C80(2009)021301(R)

behaviour of behaviour of behaviour of behaviour of nucleon picknucleon pick--up up and stripping in and stripping in mnt reactions mnt reactions mnt reactions, mnt reactions,

mainly governed by mainly governed by optimum Qoptimum Q--valuevalue

proton pick-up and neutronproton pick up and neutron stripping channels lead to

neutron rich heavy mass nuclei

X +208Pb

C.H.Dasso, G.Pollarolo, A.Winther, PRL73(1994)1907

proton stripping and neutron pick-up channels lead to neutron rich

medium mass nuclei

Xe+208Pb

Exploring the northExploring the north--east part of the nuclear chart via east part of the nuclear chart via multinucleonmultinucleontransfertransfer

region below Pb not easily accessible via

fragmentation or fission ti d it blreactions, and suitable

for multinucleon transfer

high primary cross sections of mnt channelssections of mnt channels

(mb-μb range)

BUT there areBUT there are processes lowering the final yield : evaporation

and transfer induced

V.Zagrebaev and W.Greiner, PRC83(2011)044618

and transfer induced fission

197197Au+Au+130130Te : one can populate neutron rich nuclei close to Te : one can populate neutron rich nuclei close to A ~ 130 and A ~ 200 A ~ 130 and A ~ 200

via proton stripping and neutronvia proton stripping and neutron pick-up one gets neutron rich

nuclei around A~130

in particular, the (-2p+4n) channelin particular, the ( 2p 4n) channel from 130Te would lead to the benchmark nucleus 132Sn

ia proton pick p and ne tronvia proton pick-up and neutron stripping one gets neutron rich

nuclei around A~200

in particular the (+3p 4n) channelin particular, the (+3p-4n) channel from 130Te would lead to 198Os

and beyond

L.Corradi, S.Szilner, D.Montanari et al.,

PRISMA exp May 2013

197197Au+Au+130130Te in inverse kinematics at Te in inverse kinematics at EElablab=1070 =1070 MeVMeV and and θθlablab=37=37oo

Te isotopesEnergy vs dipole curvature

radius x velocity for Te isotopes

Te isotopes

Mass vs position at the focal plane for Te isotopes

Te isotopes

197197Au+Au+130130Te in inverse kinematics at Te in inverse kinematics at EElablab=1070 =1070 MeVMeV and and θθlablab=37=37oo

Au-like ions

Mass over atomic charge state q (A/q)

for Au-like ions

After trajectory reconstruction we obtained excellent A/q resolution. The present problem is to get atomic charge states discrimination toThe present problem is to get atomic charge states discrimination to

uniquely identify final A

t X Y ΔE Et x y

High resolution kinematic coincidence between PRISMA and a second arm High resolution kinematic coincidence between PRISMA and a second arm

MWPPAC ICMCP

t, X, Y ΔE, Erest, x, y

PLFPLF oror TLFTLF in PRISMA (tagging)

PPACBC

E, ZΔE R

beam

PLF PLF oror TLF TLF in PRISMA (tagging)x, y at the entrance (MCP)

X, Y at the FP (MWPPAC)TOF (MCP MWPPAC) + E (IC) A

Trajec.MCP*

tt, X’, Y’ΔE, Range TOF (MCP‐MWPPAC) + E (IC)  APLF

ΔE, E (IC)  ZPLF

TLF TLF oror PLF PLF in the KC detectorX’, Y’ at KC angle (PPAC)  (θTLF, φTLF)ΔTOF (MCP‐MCP*), TOF (MCP*‐PPAC)E, Z, Range, ΔE (BC) 

Experimental parameters and fragment discrimination

PLF‐TLF discrimination

An axial ionization chamber followed by a position

The second arm of the PRISMA spectrometer The second arm of the PRISMA spectrometer

Frisch grid An axial ionization chamber followed by a position sensitive Parallel Plate Avalanche Counter (PPAC)

Frisch grid

Cathode

X and Y anode wire planesX and Y anode wire planes 10 μm diameter - 1 mm spacing delay-line readout 1ns

Cathode 1.5 μm thick mylar foil + Aldcathode-anodes = 2 mm E.Fioretto

Experiments using PRISMA in coincidence Experiments using PRISMA in coincidence p gp gwith the second arm with the second arm

Two experiments with PIAVE+ALPI are already scheduled in o e pe e ts t a e a eady sc edu edJune and July 2014 to study the production yield of the heavy

partner in the reactions

136Xe+208Pb and 197Au+130Te

Two LoI for SPES will be presented on the reactions

140Xe+248Cm and 132Sn+208Pb

Transfer induced fissionTransfer induced fissionTransfer induced fissionTransfer induced fission

Pfission = f(J,E*)A

aAA a’

L.Corradi et al, NIMB317(2013)743

197197Au+Au+130130Te in inverse kinematics at Te in inverse kinematics at EElablab=1300 =1300 MeVMeV and and θθlablab=27=27oo

PRISMA fields PRISMA fields settedsetted in order to detect fission fragmentsin order to detect fission fragments

PRISMA focal plane detectors setted to

optimize lighter fission fragmentsfragments

part of the detected yield should correspond to transfer induced p

fission, a mechanism suitable to produce more neutron rich nuclei

ExploitingExploiting thethe multinucleonmultinucleon transfertransfer mechanismmechanism toto getget accesaccestoto yetyet unknownunknown actinidesactinides andand transactinidestransactinides

GRAZING code calculations

using very neutron rich projectiles, via proton pick-up and neutron stripping channels, one predicts very high primary cross sections for yet unknown , p y g p y ytransactinides. Therefore, it is important to study the fission probability of

the heavy partner

Eurisol Project (key experiments) http://www.ganil.fr/eurisol/

L.Corradi, E.Fioretto, A.M.Stefanini,J.J.Valiente-Dobon

L b t i N i li di L INFN It lLaboratori Nazionali di Legnaro – INFN, Italy

D.Montanari,G.Montagnoli, F.Scarlassara, C.Michelagnoli g

Universita’ di Padova and INFN, Italy

G.Pollarolo Universita’ di Torino and INFN ItalyUniversita di Torino and INFN, Italy

S.Szilner, D.Jelavec-Malenica, T.Mijatovic, N.Soic

Ruđer Bošković Institute, Zagreb, Croatia

S.Courtin, A.Goasduff, F.HaasIPHC, Strasbourg, FranceIPHC, Strasbourg, France

C.Ur IFIN-HH, Bucharest, Romania

TransTrans--EU International Collaborations EU International Collaborations Argonne KEK -Tsukuba ANU - Canberra Dubna