Abstract
Heavy-ion microbeam system of JAEA-Takasaki is contributing for analysis of heavy-ion radiation effect and the bystander effects. Recently, there are increased interests in radiation effect of subcellular organelle such as mitochondria using fine subcellular microbeam irradiation. Nevertheless, it is difficult to generate finer beam that is capable for subcellular irradiation in our current system, because of technical difficulties in fabrication of finer micro collimator and inevitable scattering of ions at the edge of micro collimator. Thus, we installed new focusing microbeam system at another vertical beam line of AVF cyclotron of TIARA, JAEA. New system is equipped with a quadruplet quadrupole lens system for higher spatial resolution and with an X, Y beam scanner for fast hitting of single ion to micron scaled samples like a biological cell. In vacuum, a microbeam generated by the system had spatial resolution of less than 1 μm. The beam was extracted into the atmosphere, and its spatial distribution of ion was observed by irradiating ion track detector, CR39, at just beneath a vacuum window made by Kapton film of 8 μm thick. The spatial resolution of beam extracted in air was less than 5 μm, indicating that finer microbeam was generated by new focusing microbeam system. New cell targeting system for this microbeam system, which is designed to target and irradiate biological materials more precisely, is currently under development.
