Self-filtering extremely inclined X-ray crystal monochromator

Abstract

It is shown that an extremely inclined X-ray double-crystal monochromator can diffract a beam with the required wavelength and at the same time may reflect a great deal of unwanted radiation in a broad range of Bragg angles. This is a generalization of the idea of Cowan & Brennan [Rev. Sci. Instrum.(1989),60, 1987–1990], which partially solves the radiation heat load problem. The properties of such a device are discussed. It is shown that in some cases the diffracted beam may be significantly broadened as a result of refraction effects. In these cases a four-crystal arrangement or an additional mirror is necessary.