Abstract
The multi-purpose accelerator system of the Wakasa Wan Energy Research Center (W-MAST) is composed of two serially connected accelerators (a tandem accelerator and a synchrotron) and 7 beam lines.Our facility has two microbeam lines both connected to the tandem accelerator. One is magnetically focused microbeam, and the other is glass capillary-collimated microbeam.Magnetically focused microbeam line can focus proton beam to less than 1µm in diameter. It is mainly used for micro PIXE (particle induced X-ray emission) analysis.Collimated microbeam line is developed for biological use. It is also used for PIXE analysis in the air. A proton beam, being accelerated to 10 MeV by a tandem accelerator and vertically transported to the apparatus, is collimated by a glass capillary with an inner diameter of 10µm. The system is equipped with an irradiation stage with an optical microscope placed beneath the stage. Target cells are confirmed by the microscope and the location of the cells are recorded, then defined number of proton is automatically irradiated to the cells. The number and the energy of proton are detected by a silicon surface detector (SSD) put in the objective lens revolver. About 70% of irradiated proton is located within 20µm in diameter confined with CR39 track detector. This system is available to examine effects of proton beam on the individual cell attached to the culture matrix, however it is insufficient to study the effects of the beam on the cell organelles. We are improving the beam line for the irradiation to more restricted area.
