The Performance of the Compact Model of the Position Sensitive Tissue Equivalent ProportionalChamber(PS-TEPC) using an ASIC
Masanori KUBOTA, Y. Kishimoto, Kiwamu Saito, K. Takahashi, Shin‐ichi Sasaki, K. Terasawa, K. Miuchi, Aiko Nagamatsu · 2024
We are developing a position-sensitive tissue equivalent proportional chamber(PS-TEPC) as a dosimeter for the space radiation environment. The PS-TEPC is a three-dimensional time projection chamber using a position-sensitive charge collection device called as “ $\mu$-PIC” and tissue equivalent materials. The PS-TEPC can directly measure the linear energy transfer(LET) of each incident charged particle by measuring the energy deposition and the pass length in its detection volume. The LET is important amount to determine the dose equivalent due to the space radiations with high accuracy. In 2016, the performance of the PS-TEPC in an actual space radiation environment was demonstrated in the International Space Station(ISS). Currently, we aim to use the PS-TEPC in the “Gateway”, a manned lunar orbiting base. The PS-TEPC must be smaller and lighter because the transportation capability to the Moon is expected to be limited than that to the ISS. The objective of this study is to reduce the size and weight of the PS-TEPC by using an ASIC called as “LTARS2018K06A” as the signal readout circuit. In this study, a compact model of the PS-TEPC(CM PS-TEPC) was constructed by combining the detection part of the PSTEPC used in the ISS in 2016 with the LTARS2018K06A evaluation board. Then, we performed performance evaluation tests by irradiating the CM PS-TEPC with charged particle beams. From the tests, it was demonstrated that the CM PS-TEPC can acquire signals due to the incident particles and reconstruct those 3D track images. It was also demonstrated that the CM PS-TEPC can measure the LET of the incident particles with the almost lowest LET of the target LET range. From these results, it was concluded that the CM PS-TEPC has a certain feasibility as a space dosimeter.