Progress in target irradiation of individual cells using focusing heavy-ion microbeam

Funayama, Tomoo; Sakashita, Tetsuya; Yokota, Yuichiro; Kobayashi, Yasuhiko

We had developed the heavy-ion collimating microbeam system at TIARA of the Japan Atomic Energy Agency (JAEA), and utilized for analyzing heavy-ion induced biological effects. However, there is a difficulty in generating finer beam that is capable for carrying out precise subcellular irradiation in our current system, because of inevitable scattering of ions at the edge of micro collimator. Therefore, we installed new focusing microbeam system at another vertical beam line of AVF cyclotron of TIARA, JAEA. New system can focus heavy-ion beam to minimum 1 m in vacuum using a quadruplet quadrupole lens system, and equipped with an X, Y beam scanner for fast hitting of single ion to micron scaled samples. Using the system, irradiation of HeLa cells which was stained with Cell Tracker Orange fluorescent dye and inoculated on ion track detector CR39 film of 100 m thick, were carried out.