An external ion microbeam for studies of biological samples

A new external ion-beam system was developed and combined with a light ion- microbeam system in JAERI Takasaki. The system is designed for micro-partic le-induced X-ray emission analysis of biological samples in air environment with 1 mu m spatial resolution. One of the most serious problems in keepin g such a high spatial resolution is multiple scattering in a beam exit wind ow. Thin Kapton film (7.5 mu m thick) was adopted as the exit window as wel l as a sample backing foil to minimize the distance between the film and sa mples. The Lifetime of the foil under ion irradiation and spatial resolutio n of the external microbeam were investigated. The results shows that the f ilm can endure sufficient long-time irradiation to take elemental maps and the resolution can be kept nearly 1 mu m.