Advanced one-dimensional x-ray microscope for the Omega Laser Facility

An analytical study of the on-axis aperture defect (spherical aberration) convolved with diffraction, for a simple spheric-based Kirkpatrick-Baez (KB) grazing incidence x-ray microscope, indicates the optimum performance is achieved by using a short object plane to mirror distances, steep grazing angles, and high x-ray energies. Other aberrations occur for off-axis field points, but if the spherical aberration can be reduced significantly the image improvement of an extended object should be dramatic. In the quest for ultrahigh x-ray spatial resolution, the Los Alamos one-dimensional (1D) KB (at the time of writing, under fabrication) fully exploits these facts in a 40 mm working distance, steep grazing angle multilayer mirror, 4.316 keV design. A rigorous analysis of Zernike surface deformations, and all other fabrication/assembly errors indicates negligible image degradation of the predicted very high resolution performance; a similar study of existing KBs closely models the 3-5 mu m resolutions over the relevant field sizes. In addition, a novel analytical and ray trace optimization technique allows larger working distances at even higher resolutions. Due to instrument length constraints, however, this approach was not incorporated into the 4.316 keV 1DKB; although, in the future such designs could be easily accommodated on The National Ignition Facility. (C) 1999 American Institute of Physics. [S0034-6748(99)69001-3].