DEVELOPMENT OF COMPACT SOFT X-RAY SOURCE BASED ON LASER UNDULATOR *

A compact soft X-ray source is required in various research fields such as material and biological science. The laser undulator based on Compton backward scattering has been developed as a compact soft X-ray source for the biological observation at Waseda University. It is performed in a water window region (250eV- 500 eV) using the interaction between 1047 nm Nd:YLF laser and 4.6 MeV high quality electron beam generated from rf gun system. The range of energy in the water window region has K-shell absorption edges of Oxygen, Carbon and Nitrogen, which mainly constitute of living body. Since the absorption coefficient of water is much smaller than the proteins coefficient in this range, a dehydration of the specimens is not necessary. As a preliminary experiment, about 370 eV X-ray generation was carried out. In this conference, we will report results of experiments and our future plan