Development of high brightness soft x-ray source based on inverse compton scattering

Compact soft x-ray source based on inverse compton scattering have been developed at Waseda University. Using 1047 nm laser light from Nd:YLF laser scattered off 4.2 MeV electron beam generated from a photo-cathode rf-gun, we have already succeeded to generate the soft x-ray. The energy of this x-ray is included in the part of water window, in which absorption by water is much less than that of moleculars that organize a living body. Furthermore, this x-ray source has other features such as short pulse, proportional mono-energy and energy variableness. Because of these features, the application to the biological microscope has been expected. However, the flux of x-ray is not satisfied for the biological microscope application. Therefore, to multiply a soft x-ray flux, we utilized multi-pass amplifier for the laser light and improved a collision chamber. In this conference, we will report the experimental results and future plans. (author)