A new microdosimetric instrument based on a proportional scintillation imaging chamber for heavy ion track investigation

The ionization track structures formed by energetic heavy ions in matter are of great importance in radiochemistry, radiobiology, and medical applications. We proposed a proportional scintillation imaging chamber (PSIC) as a new microdosimetric instrument to investigate heavy ion track structures, since it can provide us with high-quality, real-time photographic images of ionization tracks generated by ionization radiation. We have constructed and installed a prototype of PSIC in the E5 beamline of the RIKEN Ring Cyclotron. It has been successfully operated, revealing the details of the ionization track structures (Core-Penumbra Structure) of Ar (95 MeV/u) and N (135 MeV/u) ions.