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

An analytical study of the on-axis aperture defect (spherical aberration) c onvolved with diffraction, for a simple spheric-based Kirkpatrick-Baez (KB) grazing incidence x-ray microscope, indicates the optimum performance is a chieved by using a short object plane to mirror distances, steep grazing an gles, and high x-ray energies. Other aberrations occur for off-axis field p oints, but if the spherical aberration can be reduced significantly the ima ge improvement of an extended object should be dramatic. In the quest for u ltrahigh 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 de sign. A rigorous analysis of Zernike surface deformations, and all other fa brication/assembly errors indicates negligible image degradation of the pre dicted very high resolution performance; a similar study of existing KBs cl osely models the 3-5 mu m resolutions over the relevant field sizes. In add ition, a novel analytical and ray trace optimization technique allows large r working distances at even higher resolutions. Due to instrument length co nstraints, however, this approach was not incorporated into the 4.316 keV 1 DKB; although, in the future such designs could be easily accommodated on T he National Ignition Facility. (C) 1999 American Institute of Physics. [S00 34-6748(99)69001-3].