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SAMURAI
SAMURAI @ RIBF !
!Hideaki Otsu (RIKEN Nishina Center)
!!
FRIB HRS Workshop on July 11, 2014
at Michigan State University
SAMURAI
"SAMURAI @ RIBF" Today's contents
!
1. Overview 2. History 3. Properties/Constituents 4. Experimental programs 5. Summary
SAMURAI
Superconducting Analyzer for MUlti-particle from RAdio Isotope Beam with
7Tm of bending power
RI beam from BigRIPS
target
superconducting coil
pole(2m dia.)
rotate
vacuum chamber
Kinematically complete measurements by detecting multiple particles in coincidence
Ø Superconducting Magnet 3T with 2m dia. pole (designed resolution 1/700) 80cm gap (vertical)
Ø Heavy Ion Detectors Ø Proton Detectors Ø Neutron Detectors Ø Large Vacuum Chamber Ø Rotational Stage
Invariant Mass Measurement Missing Mass Measurement
ProtonHeavy Ion
Neutron
Slide: K. Yoneda
SAMURAI ~ New Spectrometer in RIBF ~
Construc)on ~ 2011 Commissioning : 2012/03 First experiments : 2012/05
SAMURAI
SAMURAISAMURAI beam transport
Accelerator Complex
RI beam separator
DALI
SAMURAI
xn+HI (neutron-rich side) (γ, n), unbound nuclei…
p+HI (proton-rich side) (γ, p) reaction,…
p,n(target frame)+HI (p,p’), (p,2p), (p,pn), …
pol. d-induced reaction
EOS measurement
Various Physics scoped on SAMURAI
SAMURAI
Approved programs and SAMURAI configuration
xn+HI (neutron-rich side) (γ, n), unbound nuclei…
p+HI (proton-rich side) (γ, p) reaction,…
p,n(target frame)+HI (p,p’), (p,2p), (p,pn), …
pol. d-induced reaction
EOS measurement
On-‐Going On-‐Prepara)on~2014−2015
Budgetary Strategy Stage
To be advanced A>100 region
To be completed To be completed
Proposal Submitting to NPPAC on 2014/06
SAMURAI17,11: (p,n) inverse SAMURAI14: Fission SAMURAI12: Cluster on Be SAMURAI13: Polarization SAMURAI18(w/ MINOS): 2n correlation
SAMURAI15,22: EOS by π-/π+ measurement on HIC
Commissioning RUN: Day-one/two SAMURAI21(S grade): 28O SAMURAI20: 26O life SAMURAI09: Pigmy Dipole
SAMURAI
xn+HI (neutron-rich side) (γ, n), unbound nuclei…
p+HI (proton-rich side) (γ, p) reaction,…
p,n(target frame)+HI (p,p’), (p,2p), (p,pn), …
pol. d-induced reaction
EOS measurement
On-‐Going On-‐Prepara)on~2014−2015
Budgetary Strategy Stage
To be advanced A>100 region
To be completed To be completed
Proposal Submitting to NPPAC on 2014/06
SAMURAI17,11: (p,n) inverse SAMURAI14: Fission SAMURAI12: Cluster on Be SAMURAI13: Polarization SAMURAI18(w/ MINOS): 2n correlation
SAMURAI15,22: EOS by π-/π+ measurement on HIC
Commissioning RUN: Day-one/two SAMURAI21(S grade): 28O SAMURAI20: 26O life SAMURAI09: Pigmy Dipole
Ground state 5 times higher statistics Æbetter determination of energy
Excited state at ~1.3MeV First observation Most probably 2+
No peak at ~4.2MeV 19
Decay energy (MeV)
Coun
ts /1
00ke
V
27F+CÆ26OÆ24O+2n (preliminary)
Excited state(new)
Decay energy spectrum (27F+CÆ26OÆ24O+2n)
Er<200keV
Er<120keV (95% CL)
E. Lunderberg et al.PRL108, 142503 (2012)
C. Caesar et al.PRC88, 034313 (2013)
Ground state
Slide by Y. Kondo(Tokyo Tech)
Approved programs and SAMURAI setup modes
SAMURAI
SAMURAI History
SAMURAI
Designing phase
• Broadband type spectrometer was originally designed as key device in RIBF project from the beginning (~ 1997).
T. Kobayashi, TAC report, Fig. 1-3, 2004
SAMURAI
•
Magnetic spectrometer so far considered (till 2004)
T. Kobayashi, WG report, 2004
SAMURAI
QD type Magnetic spectrometer so far considered (till 2004)
T. Kobayashi, WG report, 2004 pole: 1.6(W)x 2.8 (D)x1.0m(G) field: 3.0 T @4.4MAT weight: 620 t (585 t + 35t) stored energy: 36 MJ max field on coil: 4.0 T
250MeV/ A
A/ Z=1:3
250MeV/ A:
A/ Z=1:3
(1 ) C
(2 ) Q+C
Gap 0.9m
4.4 MAT
Gap 0.3m
1.5 MAT
QD mode : C-magnet + Q
0.3m with Q
Disadvantage: Inhomogeneous Power support of SC coil, Power support for yoke Coil link for SC coil, ...
SAMURAI
Magnet construction (2009-2011)
Rails for rotatable base Rotatable base with the first layer
Magnet yoke with poles
Coils with cryostats, LHe vessels
Vacuum chamber COMPLETED 2011/03
SAMURAICommissioning Experiment March 2012
SAMURAI
• SAMURAI : large/huge acceptance broadband type • Planned on RIBF design (~1997 ?) • Construction completed : 2011 • First beam : 2012 • dδ/δ~1/1500 (achieved value), 1/1000 (designed value) • Rmax/Rmin : 2~3 • Vertical acceptance : 170mrad (± 5°) designed → 140mrad • Horizontal acceptance (for n) : 340 mrad (± 10°)
• ZeroDegree : extension of beam line from BigRIPS • Planned on RIBF design (~1997 ?) • Construction completed : 2007 • First beam : 2008 • dδ/δ=1/1240 (Large acceptance mode : 6%, H/V 90/60 mrad) • dδ/δ=1/4000 (Dispersive spectrometer mode : 4%, H/V 40/60 mrad)
Spectrometer on RIBF
SAMURAI
Spectrometer on RIBF
• ZeroDegree : extension of beam line from BigRIPS • Planned on RIBF design (~1997 ?) • Construction completed : 2007 • First beam : 2008 • dδ/δ=1/1240 (Large acceptance mode : 6%, H/V 90/60 mrad) • dδ/δ=1/4000 (Dispersive spectrometer mode : 4%, H/V 40/60 mrad) "
• SHARAQ : high resolution spectrometer for RI beam by CNS • Kick off on 2004(?) • TAC : 2005 • Construction completed : 2009 (2 years earlier than SAMURAI) • First beam : 2010 (2 years earlier than SAMURAI) • dδ/δ=1/15000
SAMURAI
SAMURAI Properties/Constituents
SAMURAI
26,27F/27,28Ne 250MeV/u (from BigRIPS)
24O
n
n
NEBULA
DALI2
MWDC
Hodoscope
Dipole Magnet 3T
Pb/C target MWDC
MWDCs
ICPlasAc ScinA.
Typical n-HI measurement Experimental setup
SAMURAI beam line detectors• Detectors for incoming beams: beam posiAon (BDC), PID(PlasAc and ICB), γ(DALI2) and tracking detector(FDC1) for electro-‐magneAc spectroscopy at SAMURAI.
STQ
DALI2
BDC1BDC2
ICBPlasJc
Target
FDC1
beam
SAMURAI Focal plane detectors• Detectors for fragments: FDC2 for tracking, HODO for ΔE and TOF, ICF for ΔE.
• Proton driQ chamber (PDC), CsI total energy detector (TED), and total internal reflecAon Cherenkov (TIRC) will come in the future.
HODO (PlasJcs)
ICFFDC2fragments
SAMURAI
Offline analysis : much better than those of on-line phase.
• On-line : 7σ separation
↓
• 13 σ separation @ A~25 →3σ separation @ A~100
(expected)
Courtesy of Y.Kondo
• Design – 240 Neutron counters – 48 VETO counters – arranged into 4 stacks
• DetecAon efficiency~40% for 1n (Currently)
• Large acceptance – 3.6m (H) x 1.8m (V) effecAve area
Half(120 modules) is funded and completed.
SAMURAI-‐NEBULANeutron-‐detecAon system for Breakup of Unstable-‐Nuclei with Large Acceptance
neutron
SAMURAI
SAMURAI Vacuum Window
• Neutron window : SUS 3mmt : 2430 × 800 mm2 • for neutrons ~ 250 MeV to pass through • De-dimension configuration applied
Estimated by ANSYS calculation → Deformation is reasonably small
The both side of Kevlar and Mylar were slacked about 5 mm to have a deflection of 40 mm in the initial condition. Kevlar and Mylar were fixed on the window frame with gluing more than 70 mm width. One day after gluing Kevlar and Mylar, this vacuum partition window was mounted on the test vacuum chamber. Achieved vacuum level was a few Pa by a rotary pump. Maximum deflection was about 60 mm. Í They elongated about 3.0 %
Vacuum system for the SAMURAI spectrometer Y. Shimizu, H. Otsu, T. Kobayashi, T. Kubo, T. Motobayashi, H. Sato, K. Yoneda
F12 STQ25
SAMURAI Beam Line SAMURAI
Vacuum Pumping System
Requirement • Lower reaction loss on partition window material. • To support itself with sufficient strength. • The area to be covered is 2430 x 800 mm2. Design • SUS304 with a thickness of 3mm. • Sectorial cylinder which has central angle of 60 degrees. • Safety factor is required to be 10. 1. To be mounted almost permanently. 2. Stress is less than 52 MPa (Tensile strength of SUS304: 520 MPa). ANSYS • Deflection and stress were calculated by using ANSYS. • Deflection: 0.22 mm • Stress: 45 MPa
Case 1: Flat board with a thickness of 3 mm O.K. : Thin thickness N.G. : Large deflection and stress
Deflection: 13.8 mm Stress: 814 MPa
Case 2: Flat board with a thickness of 30 mm O.K. : Small deflection and stress N.G. : Large reaction loss
Deflection: 0.22 mm Stress: 29 MPa
Case 3: Sectorial cylinder with a thickness of 3 mm O.K. : Small deflection and stress O.K. : Small reaction loss N.G. : Very expensive …
Deflection: 0.17 mm Stress: 43 MPa
Requirement • Lower multiple scattering and lower energy loss on partition window. • Upper limit of thickness: radiation length of L/LR ~ 10-3. To achieve the momentum resolution 1/700 • The area to be covered is 2940 x 800 mm2. • Hold vacuum Combination of Kevlar and Mylar Test of large exit window • Test window: 2800 x 1000 mm2. • Collapse 1) When the gluing was not sufficient, the collapse of foil occurred. 2) When the vacuum pressure was achieved to less 8 kPa, the Mylar elongated more 9.0 %. Î Mylar split and then collapse occurred.
• Practical point of view 1) Gluing sufficiently! 2) Not to elongate the Mylar more 9.0 %! Design • Mylar foil with thickness of 0.075 mm and width of 1250 mm. For vacuum separation • Kevlar cloth (K49 fiber) with thickness of 0.28 mm and width 0f 1270 mm. For supporting pressure • Mylar and Kevlar were glued with the Araldite to the top of a support flame which
is made of SUS304. Opening area is reduced to 2800 x 400 mm2
• In order to have a deflection of 40 mm around center region in the initial condition, the both sides of Kevlar and Mylar were slacked about 5 mm.
3D Gallery
Test of large exit window Collapsed case
Photographic of window for neutrons
Configuration of the vacuum partition window
Gluing with the Araldite
70 mm
Future development • For future experiments measuring heavy
fragments and light charged particles in coincidence, light charged particles are fully spread on the vacuum partition window.
• In order to detect light charged particles efficiently, the vacuum partition window is need to have the maximum size of 800 mm in vertically.
• We need new window frame of the form similar to the neutron window.
Mounted on SAMURAI
Vacuum test by using test chamber
Procedure for mounting Kevlar and Mylar on frame
60o
800 mm
Vacuum pumping system • Beam line: (1100 l/s TMP + rotary pump) x 1 • SAMURAI: (2400 l/s TMP + rotary pump) x 2 It took 3 hours to reach 10 Pa by two rotary pumps. In commissioning two TMPs were not used. • The vacuum level was kept around a few Pa
excepted with the vacuum leak from target chamber.
SAMURAI vacuum chamber Design • Large acceptance Horizontal space: 3.4 m Î ±10 degrees Vertical gap: 0.8 m Î ± 5 degrees Large angular acceptance for neutron • Two pipes For the (J,p) type experiment with high momentum resolution mode Auxiliary usages Accurate geometry calibration Connection with vacuum pump system • Two windows Beam entrance & vacuum pump connection Separation of heavy ions and neutrons or protons
We need two vacuum windows!!
3400 1720
1000 2820
5640
1720 1120
2430 2430
I390
The both side of Kevlar and Mylar were slacked about 5 mm to have a deflection of 40 mm in the initial condition. Kevlar and Mylar were fixed on the window frame with gluing more than 70 mm width. One day after gluing Kevlar and Mylar, this vacuum partition window was mounted on the test vacuum chamber. Achieved vacuum level was a few Pa by a rotary pump. Maximum deflection was about 60 mm. Í They elongated about 3.0 %
Vacuum system for the SAMURAI spectrometer Y. Shimizu, H. Otsu, T. Kobayashi, T. Kubo, T. Motobayashi, H. Sato, K. Yoneda
F12 STQ25
SAMURAI Beam Line SAMURAI
Vacuum Pumping System
Requirement • Lower reaction loss on partition window material. • To support itself with sufficient strength. • The area to be covered is 2430 x 800 mm2. Design • SUS304 with a thickness of 3mm. • Sectorial cylinder which has central angle of 60 degrees. • Safety factor is required to be 10. 1. To be mounted almost permanently. 2. Stress is less than 52 MPa (Tensile strength of SUS304: 520 MPa). ANSYS • Deflection and stress were calculated by using ANSYS. • Deflection: 0.22 mm • Stress: 45 MPa
Case 1: Flat board with a thickness of 3 mm O.K. : Thin thickness N.G. : Large deflection and stress
Deflection: 13.8 mm Stress: 814 MPa
Case 2: Flat board with a thickness of 30 mm O.K. : Small deflection and stress N.G. : Large reaction loss
Deflection: 0.22 mm Stress: 29 MPa
Case 3: Sectorial cylinder with a thickness of 3 mm O.K. : Small deflection and stress O.K. : Small reaction loss N.G. : Very expensive …
Deflection: 0.17 mm Stress: 43 MPa
Requirement • Lower multiple scattering and lower energy loss on partition window. • Upper limit of thickness: radiation length of L/LR ~ 10-3. To achieve the momentum resolution 1/700 • The area to be covered is 2940 x 800 mm2. • Hold vacuum Combination of Kevlar and Mylar Test of large exit window • Test window: 2800 x 1000 mm2. • Collapse 1) When the gluing was not sufficient, the collapse of foil occurred. 2) When the vacuum pressure was achieved to less 8 kPa, the Mylar elongated more 9.0 %. Î Mylar split and then collapse occurred.
• Practical point of view 1) Gluing sufficiently! 2) Not to elongate the Mylar more 9.0 %! Design • Mylar foil with thickness of 0.075 mm and width of 1250 mm. For vacuum separation • Kevlar cloth (K49 fiber) with thickness of 0.28 mm and width 0f 1270 mm. For supporting pressure • Mylar and Kevlar were glued with the Araldite to the top of a support flame which
is made of SUS304. Opening area is reduced to 2800 x 400 mm2
• In order to have a deflection of 40 mm around center region in the initial condition, the both sides of Kevlar and Mylar were slacked about 5 mm.
3D Gallery
Test of large exit window Collapsed case
Photographic of window for neutrons
Configuration of the vacuum partition window
Gluing with the Araldite
70 mm
Future development • For future experiments measuring heavy
fragments and light charged particles in coincidence, light charged particles are fully spread on the vacuum partition window.
• In order to detect light charged particles efficiently, the vacuum partition window is need to have the maximum size of 800 mm in vertically.
• We need new window frame of the form similar to the neutron window.
Mounted on SAMURAI
Vacuum test by using test chamber
Procedure for mounting Kevlar and Mylar on frame
60o
800 mm
Vacuum pumping system • Beam line: (1100 l/s TMP + rotary pump) x 1 • SAMURAI: (2400 l/s TMP + rotary pump) x 2 It took 3 hours to reach 10 Pa by two rotary pumps. In commissioning two TMPs were not used. • The vacuum level was kept around a few Pa
excepted with the vacuum leak from target chamber.
SAMURAI vacuum chamber Design • Large acceptance Horizontal space: 3.4 m Î ±10 degrees Vertical gap: 0.8 m Î ± 5 degrees Large angular acceptance for neutron • Two pipes For the (J,p) type experiment with high momentum resolution mode Auxiliary usages Accurate geometry calibration Connection with vacuum pump system • Two windows Beam entrance & vacuum pump connection Separation of heavy ions and neutrons or protons
We need two vacuum windows!!
3400 1720
1000 2820
5640
1720 1120
2430 2430
I390
CONCEPT: De-dimension 2D geometrical degree of freedom → approximately restricted to 1D deformation
Calculation results: Deflection : 0.22 mm Stress(Max.) : 29 MPa Y. Shimizu, EMIS2012 proceedings
SAMURAI
SAMURAI Vacuum Window
• Charged particle window : 2940 × 800 mm2
for HI ~ 250 MeV to pass through • 400mm → 800mm
by De-dimension concept successfully introduced on n-window
Membrane configuration : (same) Mylar 75 µm / Kevlar(K49) 0.28 mmt
Put to the practical usage on 2013/01 for Day-2 experiments
SAMURAI
Position determination of devicesupstream and downstream of the magnet
• Photo Grammetry System (PGS) • as RIKEN Common usage device , FY2010
BDC1BDC2
DALI
STQ25
Every target is identified as a green marker.
Spurious reflections are noted as red markers
1. Paste target markers on devices 2. Take pictures surrounding from the devices
Reconstruct to 3D position by dedicated software (VStars)
SAMURAI Team Leader
Establishment of position measurement by PGS unbiased by human experiences or eyes
DALIBDC1,2
STQ25
SAMURAI dipole magnet
FDC2
FDC1
Hodoscope
NEBULA
Nor
th W
all
West Wall
~1000 pictures ~800 targets (+288 coded targets)
"Overall accuracy : 300 µm(RMS)
3500mm
dZ=20 m
dX=14m
dY=4m
Scale bars
SAMURAI Day-one; 2012/05/21
3D reconstructed positions of each target marker
SAMURAI Team Leader
Scaaering Angular ResoluAon à0.9mrad (rms) Bρ ResoluAon à1/700 (one-‐path analysis) à1/1500 (sophisticated) à5σ mass resolution for A=100
Absolute momentum analysis from BDC1,2 − FDC1,2 tracking + B field(TOSCA calculation)
Here Decay energy (MeV)
Coun
ts /5
0keV
Results of precise position determination
27F+C→24O+2n (preliminary)
By Y. Kondo
Decay energy spectrum: 26O w/o artificial offsets/treatments
T.Kobayashi et al., NIMB317(2013)294-304
Each detector position (and angle) are determined within 150µm(RMS)→ Successfully reduce the large contribution of systematic error on momentum analysis
Utilized to other RIBF beam line
SAMURAI
SAMURAI experimental programs
SAMURAI
Approved experimental program and Related devices
1) “Ready” programs • SAMURAI17 M. Sasano/R.G.T. Zegar
Study of Gamow-Teller and spin-dipole transitions from 132Sn via the (p,n) reaction at 270 MeV/u
• SAMURAI11 M. SasanoStudy of Gamow-Teller transitions from 48Cr (and 64Ge) via the (p,n) reaction at 190 MeV
• SAMURAI14 D. Muecher(W. Henning)Fission Barrier Studies of Neutron-Rich Nuclei via the (p,2p) Reaction
• SAMURAI12 D. BeaumelCluster structure of Beryllium isotopes and study of multi-neutron systems
• SAMURAI13 S. SakaguchiVector analyzing power measurement for p-6He elastic scattering at 200 MeV/A
WINDS
pol-p Target
Si tele.
Only test part is ready
Done on 2014/03-04
Done partly on 2014/03-04
SAMURAI
Approved experiments (2013/12) to be performed in near future
2) Programs waiting for “User Devices” • SAMURAI15/SAMURAI22 W. G. Lynch/T. Murakami/T. Isobe/B. Tsang
Study of density dependence of the symmetry energy with the measurements of charged pion ratio in heavy RI collisions
• SAMURAI20 C. Caesar(T. Aumann)Measurement of the neutron-decay lifetime of the 26O ground state at the SAMURAI setup at RIBF
• SAMURAI21Y. Kondo Spectroscopy of unbound oxygen isotopes II : 28O → 4n Detection
• SAMURAI09R1 T. Kobayashi/Y. ToganoElectric dipole response of neutron-rich Ca isotopes
• SAMURAI18R1 A. Corsi/Y. KubotaTwo-Neutron Momentum Correlation in Borromean Nuclei
3) Programs waiting for “SAMURAI Development” • SAMURAI14 D. Muecher(W. Henning)
Fission Barrier Studies of Neutron-Rich Nuclei via the (p,2p) Reaction
MINOS/!recoil p,n detector
SAMURAI TPC
A~200 Detection @ FP
Decay Tagging
neu-LAND/MINOS
γ-CATANA
MINOS : !Operated at RIBF on 2014 Spring
SAMURAI
Submitted program on coming NP-PAC(2014/06) 4) Very new programs
• SAMURAI23 T. Isobe/T. Murakami/W. G. Lynch/B. TsangStudy of density dependence of the symmetry energy with the measurements of proton to neutron ratio in heavy RI collisions
• SAMURAI24 V. Panin(RNC)Investigation of proton-unbound states in neutron-deficient isotopes 66Se and 58Zn
• SAMURAI26 N. Iwasa(Tohoku) Study of resonance states in 34Ca using neutron removal reactions of 35,36Ca
• SAMURAI25 Z. Elekes(ATOMKI)Study of nuclear reactions relevant for type I X-ray bursts
• SAMURAI27 N. Kobayashi (UT)Spectroscopy of Odd-A Nuclei in the Island of Inversion ; 31Ne, 37Mg "
• SAMURAI19R1 S. Paschalls (TU Darmstadt)Investigation of the 4n system at SAMURAI by measuring p,pα quasi-free scattering at large momentum transfer in complete kinematics
SAMURAI 90Deg.
γ-CATANA
SAMURAI TPC
Deferred because 2weeks MT has been already approved
Approved as B grade,"Plenned to be upgrade
SAMURAI
Assembly completed May 2013
Pad plane readout tested with pulsers. Testing with cosmic rays and sources are on going. Experiments will use GET (Generic Electronics for TPC’s) readout electronics. Testing with gating grid driver is on going. TPC will be shipped to RIKEN at February 2014.
2013/9/12 Neutron Star Matter "Koubo Kenkyu"
SAMURAI TPC status
New γ-ray calorimeterCATANAYasuhiro Togano
Tokyo Institute of TechnologySupported by
Grant-In-Aid for Scientific Research on Innovative Areas“Nuclear Matter in neutron stars investigated by experiments and astronomical observations”
SAMURAI International Collaboration Workshop 2013
Slide from Sπrit group
SAMURAI
CATANA CAlorimetric deTector for rAdiation from exotic Nuclear beAms
• Study for E1 responses on medium heavy (n-rich) nuclei→ high multiplicity γ detection from residual nuclei
Setup
neutrons
charged fragments
Beamγ
NEBULA
DALI2CATANADALI →
CATANA•CAlorimetric deTector for rAdiations from exotic Nuclear
beAms
• Crystals: CsI
Beam
15 cmt/9.5cmt CsI(Na) array
New γ-ray calorimeterCATANAYasuhiro Togano
Tokyo Institute of TechnologySupported by
Grant-In-Aid for Scientific Research on Innovative Areas“Nuclear Matter in neutron stars investigated by experiments and astronomical observations”
SAMURAI International Collaboration Workshop 2013
Ready on 2015
εγ(1MeV) : 25%(DALI) → 65%(CATANA)CATANA
Slide from Y. Togano
SAMURAI
Summary
• SAMURAI Overview • History
• Properties/Constituents • dδ/δ~1/1500 (achieved value), • dA/A ~ 1/300 (achieved value, governed by lack of TOF resolution)
• to be improved up to design value of 1/500 (5σ on A~100)
• Experimental programs • Experiments with each SAMURAI configuration proposed • Several programs are waiting for MT assignment • Various user devices will be introduced coupled with
SAMURAI (??? because of simplicity of SAMURAI ???)
SAMURAI
One more thing…
• SAMURAI ⇄ SHARAQ • SAMURAI : Neutron detection but limited resolution • SHARAQ : high resolution but no chance on neutron "
• + no chance to extend Zero degree type spectrometer downstream of SAMURAI because of limitation of building "
• So, I think high resolution property coupled with neutron detection is very unique,even if it is designed on R3B-Grad magnetic spectrometer. "
• QD for HI-p configuration for recovering vertical divergence.