Abstract
Target irradiation of individual cells using heavy-ion microbeam is a useful means for measuring exact hit effect of heavy-ion on cell. Moreover, heavy-ion microbeam is a powerful tool for analyzing mechanisms underlying radiation-induced bystander effect, which is induced on a cell population exposed to low fluence, low dose radiation. Thus we installed a focusing heavy-ion microbeam system under a vertical beam line of an AVF cyclotron of JAEA-Takasaki, and developed a method to irradiate individual cells using focusing heavy-ion microbeam. To improve a throughput of the cell irradiation using focusing microbeam, we developed a code that calculates voltages, which will be applied to a beam scanner for moving beam spot rapidly to the target positions. Using a developed code, a set of voltages was calculated from a pre-obtained cell image, and a film of CR-39 was irradiated by scanned beam according to the calculated voltages. After irradiation, hit positions of ion were visualized as etch pits, and the spatial distribution of them was observed. The distribution pattern of source cell image and etch pits on CR-39 film were well correlated, so that it was suggested that the developed code can finely convert detected cell positions to corresponding scanner voltages. Thus we concluded that using the code we will become able to irradiate cell rapidly with scanned heavy-ion microbeam.
