A SHORT BASELINE NEUTRINO FACILITY (SBLNF) IN THE CERN NORTH AREA: DESIGN OVERVIEWM. Calviani, I. Efthymiopoulos, A. Ferrari, B. Goddard, R. Losito, J. Osborne, P. Sala, L. Scibile, R. Steerenberg, H. Vincke
8th INTERNATIONAL WORKSHOP ON NEUTRINO BEAMS &
INSTRUMENTATIONNBI2012 – 6th/10th November 2012
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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Outline
7th November 2012 (NBI2012)
Introduction to the Short Baseline Neutrino Facility Study Group
Experimental requirements Preliminary parameters of the
installation Proto-layout of the installation Neutrino production area configuration Open points and challenges Conclusions
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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7th November 2012 (NBI2012)
Introduction to the Short Baseline Neutrino Facility Study Group
Experimental requirements Preliminary parameters of the
installation Proto-layout of the installation Neutrino production area configuration Open points and challenges Conclusions
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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SBLNF study group
7th November 2012 (NBI2012)
A SBLNF study group has been convened to address the feasibility of a short baseline neutrino facility in the CERN North Area
This should serve primarily the ICARUS/NESSiE experiment (C. Rubbia et al., SPSC-P-347) as well as a neutrino test area for detector R&D and neutrino cross-section measurement
Why not use CNGS? Target area very deep (~60m), too costly to install new
detectors underground DP configuration not adapted for a low energy neutrino
beam
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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7th November 2012 (NBI2012)
Introduction to the Short Baseline Neutrino Facility Study Group
Experimental requirements Preliminary parameters of the
installation Proto-layout of the installation Neutrino production area configuration Open points and challenges Conclusions
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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Experimental requirements
Sterile neutrino physics (C. Rubbia et al., SPSC-P-347): Exploring the possible existence of one or more sterile
neutrino Search for spectral differences of electron-like specific
signatures in two identical detectors at two different neutrino decay distances
7th November 2012 (NBI2012)
nm+anti-nm
ne+anti-ne
An exact proportionality between two ne spectra implies absence of neutrino oscillations
1600 m: ICARUS T600 detector + magnetic spectrometer (NESSiE)
350 m: new 150 LAr-TPC detector + magnetic spectrometer (NESSiE)
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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7th November 2012 (NBI2012)
Introduction to the Short Baseline Neutrino Facility Study Group
Experimental requirements Preliminary parameters of the
installation Proto-layout of the installation Neutrino production area configuration Open points and challenges Conclusions
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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Preliminary parameters of the installation
7th November 2012 (NBI2012)
100 GeV/c beam momentum Neutrino spectrum peaked at ~2 GeV ND at 350 meters, FD at 1600 meters, middle
position detector at ~700 meters from target DP: length ~80-120 m, radius 100/200 cm
DV of 100 meters is the experiment minimum requirement
Hadron absorber: Graphite core, 2-3 meters long, 1x1 m2 surface Segmented Fe blocks (10/18 meters in total)
Beam line at around 10/15 meters from “ground”
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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CERN accelerator complex
7th November 2012 (NBI2012)
SBLN
F
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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Primary beam configuration
7th November 2012 (NBI2012)
100 GeV/c baseline primary beam momentum 3.5*1013 p/pulse (4.5*1013 p/pulse ultimate
running) 6s (3.6s min) repetition rate ~100 kW (200 kW) beam power Time sharing between fixed-target physics
Yearly POTs between ~3-4.5*1019 p+/yr New extraction lines from existing tunnels Beam 1s on target: 1-2.5 mm, divergence ≤1
mrad
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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Beam extraction from SPS
7th November 2012 (NBI2012)
Magnetic septa
(MST+MSE)
Short baseline neutrino beam
Beam excitation via injection kicker in LSS1 + extraction via existing septa
Solution tested for low intensities during recent beam tests
B. Goddard
Fast extraction not available in the SPS North Area branch (complex to install a new kicker in a short time)
Injection kicker (MKP)
slow
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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7th November 2012 (NBI2012)
Introduction to the Short Baseline Neutrino Facility Study Group
Experimental requirements Preliminary parameters of the
installation Proto-layout of the installation Neutrino production area configuration Open points and challenges Conclusions
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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7th November 2012 (NBI2012)
Beam line ~parallel to the existing North Area lines
New production infrastructure
Experiments and neutrino beam test areas
Target area
Near detector~350 meters
Testing area for new generation detectors
Far detector~1.6 km
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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Muon fluence and constraints
7th November 2012 (NBI2012)
Decay pipe
Hadr
on st
oppe
r
Moraine soil
Proton momentum
Muon range (from target)
100 GeV/c ~320 meters
110 GeV/c ~340 meters
120 GeV/c ~360 meters
Assumptions: 4.5*1013 p/pulse 1.9 g/cm3 moraine density DP 100 m long HS: 3 m core + 7 m Fe
ND should be at least at 350 meter from target!
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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7th November 2012 (NBI2012)
Introduction to the Short Baseline Neutrino Facility Study Group
Experimental requirements Preliminary parameters of the
installation Proto-layout of the installation Neutrino production area configuration Open points and challenges Conclusions
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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Neutrino beam production area configuration
7th November 2012 (NBI2012)
The baseline configuration of the target area inspired by both AP0/NuMI “chase” and T2K: No direct personnel access close to production
elements Reduced number of equipment in hot zones Remote maintenance on all equipment Reduced air volume around the production elements Allow for target volume and decay pipe under He
environment (TS and DP separated in case of access) Shallow depth calls for heavy shielding around target
trench and decay pipe
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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(Proto) layout of the installation (FLUKA)
7th November 2012 (NBI2012)
Ground (moraine)
Decay pipeDecay pipe shielding
Hadron stopperTarget station building and
vault
Primary beam area
Target chase
Target shielding
FLUKA preliminary implementation:Shielding thickness not optimized!
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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(Proto) layout of the installation (FLUKA)
7th November 2012 (NBI2012)
Ground (moraine)
Target chase
He vessel (medium blue)
Concrete shielding (red)
Iron shielding (dark blue)
Target station building and vault
Target & horn/reflector
300
cm20
0 cm
300 cm
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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Absorber/m stations
7th November 2012 (NBI2012)
Hadron absorber: Effective iron length of 10/18
meters Water cooling system (surface)
Muon pits (i.e., diamond-detectors): Pit 1 inside the dump to be sensitive
to low energy m (~5 GeV) Pit 2 downstream the absorber Access via a dedicated surface building
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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Potential target configuration
7th November 2012 (NBI2012)
CNGS target design Cooling by radiative
emission and partly by convective exchange
Graphite at high temperature (~1000 °C)
Revolver structure would have allowed to exchange remotely target without interventions
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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Potential target configuration
7th November 2012 (NBI2012)
SBLNF: CNGS-like “evolutionary” design graphite/beryllium options under investigation Simpler construction and more diagnostics Complete remote manipulation Possibility to have a closed He-loop cooling
(enhanced convection) – external air blow could be avoided Pressurized circuit with an external heat exchanger
No segmentation required by physics Larger rod and beam radius (~4-10 mm radius)
Reduced off-axis vibration issues Enhanced production of low energy p/K PRELIMINARY
DESIGN ON-
GOING
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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Potential target configuration
7th November 2012 (NBI2012)
Advantages DisadvantagesTarget inside horn
Higher pion collection from target
More difficult maintenance and construction
Less degree of freedom for target design
Electrical coupling between target/horn
Target outside horn
Easier maintenance and installation
More degree of freedom for a more robust design
Less efficient in pion collection
For both solution the baseline is to have a passive or actively He-cooled target
PROS & CONS
TO BE STUDIED
IN DETAIL
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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7th November 2012 (NBI2012)
Introduction to the Short Baseline Neutrino Facility Study Group
Experimental requirements Preliminary parameters of the
installation Proto-layout of the installation Neutrino production area configuration Open points and challenges Conclusions
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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Preliminary radioprotection aspects
7th November 2012 (NBI2012)
Optimisation: annual dose <100 mSv for exposed personnel (<10 mSv for general public)
CERN dose limits: 6 mSv/y or 20 mSv/y (for radiation workers), 1 mSv for other
personnel working at CERN and 0.3 mSv/y for general public
Detailed studies to follow: Required shielding (thickness, material choice) Induced radioactivity (structure, surroundings, soil, groundwater) Optimization of design to minimize intervention doses for
maintenance personnel Waste & decommissioning
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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Preliminary radioprotection aspects
7th November 2012 (NBI2012)
H*(10) with the current shielding: In the target vault <10 mSv/h Above DP, At 15 m from beam axis
< 1 mSv/h Values manageable with a proper
shielding design
PRELIMINARY
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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Challenges in the design
7th November 2012 (NBI2012)
He vessel for TS/DP: Material/thickness? He at atmospheric pressure? Closed loop with recirculation? Purge system? Constraints in He purity for a C/Be target? Which shielding elements should be included in the
vessel? Separate volume via appropriate shutter (closed
during access) to avoid purging the DP volume
Several technical questions concerning the engineering of the installation are still open
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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Challenges in the design
7th November 2012 (NBI2012)
Target: In case of a He-cooled target, shall we keep the target
and He-vessel circuits separated? How critical is the purity in the He-loop?
Shielding: Inner iron layer water/air cooled (~50 kW deposited)? Decay pipe inner layer shall be water cooled (T2K-like?)
Soil/water activation minimization: Groundwater mobility for surface layers? Careful design of the interface between activation zone
and surrounding earth Radioactive gas emission in the TS
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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7th November 2012 (NBI2012)
Introduction to the Short Baseline Neutrino Facility Study Group
Experimental requirements Preliminary parameters of the
installation Proto-layout of the installation Neutrino production area configuration Open points and challenges Conclusions
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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Conclusions
7th November 2012 (NBI2012)
A study group has started addressing the technical feasibility of a short baseline neutrino facility in the CERN North Area
It would be a 100 GeV/c p+ beam, ~200 kW installation, at shallow depth (10/15 m)
Neutrino production area to be a “chase”-based design
Significant design efforts to be dedicated in 2013 to have it operational in the next few years
Design experience from NBI colleagues will be precious, considering feedback from running
installations (T2K/NuMI/NoVA)
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M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
Backup
7th November 2012 (NBI2012)
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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(Proto) layout of the installation
7th November 2012 (NBI2012)
Main target vault, housing: Target/horn/reflector
trench Radioactive storage
area A temporary shielded
area - fast inspection and “easy” repair
Annex service building: general services and
assembly
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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Open points: TS energy deposition
Target: ~1.5 kW “Chase” iron shielding:
~50 kW deposited power
Air/He cooling necessary?
DP shielding: ~68 kW on the first 50
cm layer thermal cracking?
Mitigation strategy to be further investigated
Region kJ/pulse kW (average)Target 5.62 1.56Top Fe shielding (layer 1) 48.32 13.42Lateral Fe shielding 57.50 15.97Bottom Fe shielding 55.42 15.39Decay pipe shielding (total) 258.56 71.82Hadron stopper (graphite) 159.54 44.32Hadron stopper (iron) 123.70 34.36Horn (total) 7.01 1.95Reflector (total) 5.05 1.40
7th November 2012 (NBI2012)
M. Calviani et al., Short Baseline neutrino facility (SBLNF) design overview
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Layout considerations
7th November 2012 (NBI2012)
The position of the target is constrained by: Existing buildings Bending radius of
the extraction line The near detector
distance from target and existing buildings