System of cell irradiation with a precise number of heavy ions

Kobayashi, Yasuhiko; Funayama, Tomoo; Wada, Seiichi*; Taguchi, Mitsumasa; Watanabe, Hiroshi

A single cell irradiation system has been developed for targeting cells individually with a precise number of heavy ions to elucidate radiobiological effects of exactly one particle and to investigate the biological effects of low fluence irradiation with HZE particles. Using the heavy ion microbeam apparatus installed at JAERI-Takasaki, mammalian cells were irradiated in the atmosphere with a single or precise numbers of ions, 13.0 MeV/u 20Ne or 11.5 MeV/u 40Ar. The number of ions traversed the cells attached on the ion track detector CR-39 were counted with a plastic scintillator. Immediately after the irradiation, the position and the number of ion tracks traversed the cell was detected with etching of CR-39 from the opposite side of the cell with alkaline-ethanol solution at 37C. The growths of the cells were observed individually up to 60 hours after irradiation.