Profile of energy deposition in human body irradiated by heavy ions

Sato, Tatsuhiko   ; Tsuda, Shuichi  ; Sakamoto, Yukio; Yamaguchi, Yasuhiro; Niita, Koji*

Radiological protection against heavy ions has been an essential issue in the planning of long term space missions. We performed Monte Carlo calculations of dose distributions in terms of the linear energy transfer (LET) of ionizing particles using Particle and Heavy Ion Transport code System, PHITS, for incidences of various kinds of heavy ions with energies up to 3 GeV/A. Based on the results, we found that large amounts of energies are imparted by particles with an LET above 10 keV/mm even for the incidences of heavy ions with high energies. This tendency is different from that for high energy hadron incidences, where more than 80% of the total deposited energies are imparted by particles with an LET below 10 keV/mm.