1. 1. Introduction Secondary Heavy charged particle (fragment) production
by neutron and proton
cause a large local ionization due to its large LET
Important for estimation of radiation effect
dosimetry for human
single event upset (SEU) for semiconductor device by cosmic rays
Especially, Energy and angular double differential cross-section data of fragments are Required.
However,
Data status are very poor among experiments & calculations
Difficulty in the measurement (low yields, large energy loss etc.)
Very difficult to measure by Counter telescope (ΔE-E method)

2. 1-2. Fragment measurement
In study of nuclear physics and
elastic recoil detection analysis (ERDA)
S. Grigull et al. Nucl. Inst. and Meth. B132(1997)

3. 2. In this study Goal We adopted for fragment measurement
1) a Bragg curve spectrometer (BCS)
having the capability of various information with a single counter and
2) an energy-time of fight (E-TOF) method having the capability of
mass discrimination in almost all energy region for charged particle beam.
For each
1) Development the fragment measurement system
2) Test measurement (BCS: done, E-TOF: near future)
Goal
Obtain Energy and angular double differential cross-section data of fragments
induced by neutron (BCS) and proton (BCS,E-TOF)
Evaluation of model calculation
Evaluation for dosimetry and SEU effect

4. 3. Bragg Curve Spectrometer [BCS]
Bragg curve spectrometer (BCS) based on gridded ionization chamber (GIC)
capability of various information (energy, charge, mass ) with a single counter
Bragg peak  f(Z)
Total energy vs Bragg peak  Particle Identification (usually)
No E counter, large solid angle and particle acceptance

5. 3-2. The present BCS For neutron induced reaction Special care
１．Inner sample， High Z electrodes (Ta)， Use cathode signal　　
Low pressure gas : Only fragments
homogeneous electric field

6. 3-3. measurement system 3-3.2. Electronic circuit
Gas flow system
Electronic circuit
Different time constant AMPs
Obtained parameter
・Cathode PH
・Anode PH
・Bragg peak PH
・Cathode-Anode Timing
Keep the gas pressure to 200 torr

7. 3-4. Experiment for Proton induced reaction
Experimental apparatus
・Target： Carbon (100μm)
Silicon (500μm)
Polyethylene (4μm)
Aluminum (2μm)
・Angle： 30°
・Incident particle： proton
70 MeV，~4 nA
・Irradiation time：~2 hour

8. 3-5. Results for proton induced reactions
Bragg peak vs. Anode
Simulation with TRIM code
Good agreement
Remove with C-A timing
Good identification
（He~B）

9. 3-5.2.Comparison of separation method
Bragg peak vs. Anode
Anode vs. C-A timing
Better

10. 3-5.3. Results for thick samples
・Target： Carbon (100μm)
Silicon (500μm)

11. 3-5.3. Results for thin samples
・Target： Polyethylene (4μm)
Aluminum (2μm)

12. 3-6. Experiment for Neutron induced reaction
JAERI TIARA　Li(p,n) En=65MeV
n=1.26104 [n/cm2 /C]
Incident beam :collimated neutron
sample　C(100,200m)、Ni(100m)、Al(6m)
　→　evaluation of foreground and background events
Proton current 1A　~4 hour irradiation
Pa=E+σPc
Pc=E(1-x/d cosθ)
Large area
Large solid angle

13. 3-7. Results for neutron induced reaction
3.7.1．Carbon 0.1mm
3.7.2．Nickel 0.1mm
response for emission angle
BG from gas
TRIM calc.
3.7.3．Carbon 0.2mm
3.7.4．Aluminum 0.006mm
Different thickness
BG from chamber

14. 3-7.5. Results for identification

15. 3-7.6. Energy spectra (He, Li)
 particle
Lithium

16. 3-7.7. Energy spectra (Be, B, C)
Beryllium
Boron
Carbon

17. 4. Energy-TOF method (E-TOF)
Low threshold Large energy range Very small solid angle !
 TOF
Timing Energy
Detect Detect.

18. 4-2. E-TOF Chamber Timing Detector :MCP Energy Detector :SSD p
Timing detecting telescope
Sample
Complete!；
Experiments will start at CYRIC near future.

19. 5. Summary 1. Energy-angular distribution measurements were done for
Proton induced and
Neutron induced
He, Li, Be, B, C emission reaction with thick C, Si and thin polyethylene Al targets with BCS,
2. Proton data
clearly identify emitted particles with their charge, and
in fair agreement with TRIM calculation
The DDX data were obtained by thin targets.
3. Neutron data
The energy spectra of thick target were obtained　
The identification were not good due to emitted angle distribution

20. 6. For future
1. BCS
Improvement of BCS for collimation, sample changer
Digital wave form analysis
Correction data with new BCS
2. E-TOF
Correction data　(proton induced reaction)
Comparison with data from BCS (charge dist.) and E-TOF (mass dist.)

21. New BCS： 1) wide space （noise decreasing） （complete
New BCS： 1) wide space （noise decreasing） 　（complete!） 2) tight collimation （noise decreasing ） ) sample changer（BG evaluation）　
Sample changer

22. Reference H.Ochiishi et al. : Nucl. Instr. and Meth. A 369 (1996) 269
Application of Bragg-curve counters to a target multifragmentation measurement
M.Baba et al. : Nucl. Instr. and Meth. A 428 (1999) 454
Characterization of a MeV (p,n) neutron source TIARA using a proton recoil telescope and a TOF method
C.R.Gruhn et al. : Nucl. Instr. and Meth. 196 (1982) 33
Bragg curve spectroscopy
T. Sanami et al. : Nucl. Instr. and Meth. A 440 (2000) 403
(n,α) Cross-section measurement using a gaseous sample and a gridded ionization chamber
N. Ito et al. : Nucl. Instr. and Meth. A 337 (1994) 474
Large solid angle spectrometer for the measurements of differential (n, charged-particle) cross sections
A. D. Frawley et al. : Nucl. Instr. and Meth. A 306 (1991) 512
A large solid angle, high stopping power Bragg curve spectrometer for coincidence measurements