Development of laser-driven quasi-monoenergetic proton beam line for radiobiology

放射線生物研究用レーザー駆動準単エネルギー陽子ビームラインの開発

余語 覚文; 前田 拓也; 堀 利彦; 榊 泰直; 小倉 浩一; 西内 満美子; 匂坂 明人; Bolton, P.; 村上 昌雄*; 河西 俊一; 近藤 公伯

Yogo, Akifumi; Maeda, Takuya; Hori, Toshihiko; Sakaki, Hironao; Ogura, Koichi; Nishiuchi, Mamiko; Sagisaka, Akito; Bolton, P.; Murakami, Masao*; Kawanishi, Shunichi; Kondo, Kiminori

We report on the development of quasi-monoenergetic proton irradiation system driven by laser and its application to radiobiological studies. Protons accelerated by W/cm laser pulses are energy-selected by quadruple-dipole magnets (QDM) and delivered with an energy peak at 2.25 MeV and energy spread of 0.66 MeV on the full width at half maximum (FWHM). Cell survival ratio is measured with a colony formation assay for cell samples from human salivary grand tumor (HSG cells) after the proton irradiation up to 8 Gy with successive bunches having a dose rate of Gy/s. We report on the results of RBE (relative biological effectiveness) measurement, which is the first one for laser-accelerated ions.