APPARATUS AND METHOD FOR FOCUSING HARD X-RAYS

摘要

APPARATUS AND METHOD FOR FOCUSING HARD X-RAYS A dislocation-free, composite-substance crystal having a lattice constant which decreases over the length of the crystal (38) convergently focuses beams of hard X-rays or gamma rays (11). A single-substance, dislocation-free crystal (34) collimates diffuse beams of hard X-rays or gamma rays and projects the collimated radiation (11') to the focusing crystal (38). A mask (36) is interposed between the collimating crystal (34) and the focusing crystal (38) causing the collimated radiation (11'') to carry an image of the mask (36). The focusing crystal (38) produces a convergent hard X-ray beam or gamma ray beam (11''') to focus a reduced image of the mask (36) upon the photosensitive layer (41) of a water (39). An example of a dislocation-free crystal having a lattice constant which decreases over its length (38) is a dislocation-free silicongermanium crystal (20) wherein the proportion of germanium to silicon varies over the length of the crystal.