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)

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)709-717

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

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

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

3-3. measurement system 3-3.2. Electronic circuit 3-3.1. Gas flow system 3-3.2. 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

3-4. Experiment for Proton induced reaction 3-4.1. Experimental apparatus ・Target： Carbon (100μm) Silicon (500μm) Polyethylene (4μm) Aluminum (2μm) ・Angle： 30° ・Incident particle： proton 70 MeV，~4 nA ・Irradiation time：~2 hour

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）

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

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

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

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

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

3-7.5. Results for identification

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

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

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

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

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

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.)

New BCS： 1) wide space （noise decreasing） （complete New BCS： 1) wide space （noise decreasing） 　（complete!） 2) tight collimation （noise decreasing ） 3) sample changer（BG evaluation）　 Sample changer

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 40-90 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