2016 年 30 巻 p. 8-16
Considering further human activity in space, it is necessary to study the biological effects of combined microgravity and space radiation; however, many aspects of these combined effects remain unclear. In the field of space biology, it is difficult to investigate relative biological effectiveness (RBE) and combined effects because the ability to conduct and replicate space experiments is restricted. Therefore, a new three-dimensional (3D) clinostat synchronized X-irradiation system with a high-speed shutter was fabricated following the development of a heavy-ion irradiation system. This study showed that the system could simultaneously irradiate rotating samples using the 3D clinostat, with the samples in a horizontal position. The samples were completely irradiated because of the flatness and symmetry of the irradiation fields. Doses were virtually identical under both standing and rotation conditions, with the difference being <1% under the assumption of X-irradiation at a dose of 1 Gy. Our new device could accurately synchronize X-irradiation and simulated microgravity at the ground level. The device is expected to greatly contribute to space radiation research as a valuable platform for studies concerning RBE and the combined effects of radiation under microgravity.