a Total Transverse-Aberration Function for X-Ray Optics.

Laser fusion may become an important energy source of the future. One of the by-products of the laser fusion process is a large flux of low-energy x-rays, emitted from a small glass pellet. To further the development of laser fusion, it is necessary to photograph these x-rays. In order to secure images of sufficient resolution, it is necessary to focus the x-rays. At present, the only feasible method of focusing x-rays is by external reflection from a suitably shaped surface. In the case of x-rays, external reflection occurs only at very small grazing angles of incidence. With such small angles, certain geometrical aberrations severely limit the quality of the image obtainable. This report represents a theoretical study of the total transverse aberration, or blur, to be expected when the imaging is accomplished by reflection from the concave surface of a section of a right circular cylinder. An expression for the blur is derived and expanded in a Maclaurin series. The terms in this series show the dependence of well-known aberrations on the applicable system parameters. It is hoped that this will be a useful tool, in future x-ray optical work, for adjusting the various parameters, so as to reduce the more prominent aberrations.