Fuminobu Saiho

A simple method of energy calibration for thin plastic scintillator

A thin plastic scintillator is used as a trigger counter of charged particle spectrometers. Since its Compton edge is not clear, it is difficult to check up the thin plastic scintillator counters with a standard gamma-ray source. In this paper a simple method is proposed to determine the Compton edge and the energy resolution of the thin plastic scintillator by fitting the simulated spectrum to the measured. The simulated spectrum was made with a Monte Carlo program considering geometries of the plastic scintillator. This technique was examined with the plastic scintillator having thickness of 2 mm to 10 mm.

Development of Gas Proportional Scintillation Counter for Light Heavy‐Ion Detection

In recent years, nuclear data have been needed in the medical field. Nuclear data induced by light heavy ions are especially needed at high precision for cancer treatment, although there are not enough usable data at present.We have a plan to measure light heavy‐ion nuclear data with a dE‐E detector. Low density is needed for the dE detector. We have two options for the dE detector: a semiconductor detector (SSD) and a Gas Counter. On one hand, SSD has good energy resolution, but on the other hand, it is expensive and its decay time is on the 100‐microsecond order. A Gas Counter is inexpensive, and a Gas Proportional Scintillation Counter (GPSC) has fast decay time. Then, we developed a GPSC for the dE detector, and its evaluation experiment was carried out at the Heavy Ion Medical Accelerator in Chiba (HIMAC).We will report the results of the experiment with the performance of the GPSC.

Study of Proton and Deuteron Spectra from Proton Induced Reactions at Intermediate Energies

Intermediate-energy nucleon-nucleus interactions were investigated in order to achieve a more comprehensive understanding of spallation reaction and heavier fragments productions. Measurements of proton and deuteron production reactions for 300- and 392 MeV proton incidence were carried out at RCNP ring-cyclotron facility. Inclusive 12C(p, p′x) and 12C(p, dx) spectra at 300 MeV were measured in a wide energy range and compared with two theoretical calculations: the quantum molecular dynamics model and the intranuclear cascade model. The calculations of the INC model were in good agreement with the experimental results in the quasifree region. The deuteron production cross sections calculated by the QMD model were much smaller than the ones obtained by the measurement. The cause of this discrepancy was discussed in terms of a deuteron knockout process.

Proton Production Cross Sections for Reactions Induced by 300‐ and 392‐MeV Protons

Multistep direct processes in proton production reactions were investigated with proton beam of 300‐ and 392‐MeV bombarding targets nuclei. The targets nuclei are 181Ta, 197Au, and 209Bi for 392 MeV and 197Au for 300 MeV protons. Energy spectra were measured at several laboratory angles from 20° to 105° and compared with two theoretical models, the quantum molecular dynamics and the intranuclear cascade model. At intermediate energy, the double differential cross section is sensitive to ground state in codes. We found that a more realistic ground state led better accounting of measured data.

Proton production cross sections for reactions induced by 300- and 392-mev protons

Multistep direct processes in proton production reactions were investigated with proton beams of 300 and 392 MeV bombarding five target nuclei, 12C, 16O, 27Al, 93Nb and 197Au. Energy spectra were measured at eleven laboratory angles from 19 deg to 104 deg and compared with two theoretical models, the quantum molecular dynamics and the intranuclear cascade model.