Harmonic-free and fixed-exit monolithic X-ray monochromator

Abstract

It is shown that if the second wall of a channel-cut crystal x-ray monochromator is properly curved, the monochromator is harmonic free for allθ. Moreover, if the first wall is suitably inclined to the diffracting planes, the position of the exit beam may be kept constant for allθ. This requires a correction of the position of the monochromator for eachθ by its axial and radial translation.