Evaluation of delta-rays production in a wall-less tissue equivalent proportional counter irradiated by energetic heavy ion beams

Tsuda, Shuichi  ; Sato, Tatsuhiko   ; Iwase, Hiroshi*; Namito, Yoshihito*; Sasaki, Shinichi*

Deposit energy distributions of secondary high-energy electrons, delta-rays, have been calculated in a wall/wall-less tissue equivalent proportional counter, TEPC, using Monte Carlo simulation code EGS5. It is found that wall-less TEPCs are indispensable for lineal energy distribution in tissue equivalent gas irradiated by energetic heavy ion beams.