Table-Top Soft X-Ray Microscope Imaging System with a Laser-Produced Plasma X-Ray Source

We developed laser-produced plasma X-ray sources using femtosecond laser pulses at 10 Hz repetition rate in a table-top size to investigate basic mechanism of X-ray emission from laser-matter interactions and its application to an X-ray microscope. In a soft X-ray region, laser-plasma X-ray emission from a solid target achieved an intense flux of photons of the order of 1011 photons/rad per pulse with duration of a few hundreds ps, which is intense enough to make a clear imaging in a short time exposure. As an application of laser-produced plasma X-ray source, we developed soft X-ray imaging microscope operating at the wavelength of 13.9 nm. The microscope consists of a cylindrically ellipsoidal condenser mirror and a Schwarzschild objective mirror with highly-reflective multilayer. We report results of performance tests and biological cell observations of the soft X-ray imaging microscope with a compact laser-produced plasma X-ray source.