Schwarzschild microscope at the wavelength of 18 nm using a laser-produced plasma source

Abstract

The design , construction and imaging experiments of a soft X-ray microscope which consists of acompact laser-produced plasma source (LPPS) , as well as a multilayer coated spherical condenser, and Schwarzschild optics are presented. The Schwarzschild optics was designed for numerical aperture of 0. 1 and magnification of 10. For the working wavelength of 18 nm calculations show that the resolution is expected to be 0.2im. We designed a 41 layer Mo/Si multilayer coatings of throughput centered at l8nm, and these coatings were deposited by magnetron sputtering. We put a Al/C multilayer filter in front of the image to block thelong wavelength radiation. The object on the primary experiments is a piece of Cu mesh of 55 pair lines/mm witha opening of 5m and bar width of 3im. The backlit mesh image were taken on Kodak X-ray film. The first lot of experiment data show that a spatial resolution better than 1im was obtained. Key words : Schwarzschild Optics , Soft X-Ray Microscope , Multilayer mirrors.