Measurement of lineal energy distribution by a wall-less tissue equivalent proportional counter for heavy ion beams

Tsuda, Shuichi  ; Sato, Tatsuhiko   ; Takahashi, Fumiaki  ; Satoh, Daiki   ; Endo, Akira   ; Sasaki, Shinichi*; Namito, Yoshihito*; Iwase, Hiroshi*; Ban, Shuichi*; Takada, Masashi*

Knowledge of energy deposition at micrometer dimensions along heavy ion tracks is essential to understand the biological effects of radiation. Wall-less tissue equivalent proportional counter (wall-less TEPC) was produced for the purpose of measurement of lineal energy distribution including secondary-produced high-energy electrons, delta-rays. The measurement using the wall-less TEPC was performed at Heavy Ion Medical Accelerator at NIRS, Japan. It is found that lineal energy distributions could be measured for primary carbon beam with energy of 400MeV per nucleon and delta-rays. Detail of the experiment, energy calibration and estimation of delta-rays production will be presented.