Development of laser plasma-based soft x-ray microscopy

Abstract

A compact soft X-ray microscope system has been developed for biological applications with nano-scale resolution. Soft X-ray used to the system is emitted from a solid target by using Nd-YAG pulsed laser. Boron nitride (BN) is used as the target materials in the system. The optics of the microscope system is adopted with wolter type-I mirrors, which is consisted of a condenser mirror with demagnification of 1/4× and an object mirror with magnification of 32×. The surface roughness of the machined wolter mirrors is about 0.8 nm (Ra) after polishing. In this paper, the X-ray characteristics, i.e., spectrum and intensity emitted from laser plasma-based x-ray source was measured. Imaging test using the system was performed with gold 2000 mesh. The spatial resolution of the soft x-ray microscope system was obtained about 900 nm.