A double crystal multilayer x-ray monochromator

Abstract

A tunable double crystal x-ray monochromator using matched pairs of multilayer-coated mirrors has been designed and constructed at the CfA. Each set of mirrors is usable over a factor of three range of wavelengths and by changing the mirrors the mechanism can be used at wavelengths of 10 to >300 Å (40ev to 1.2kev). The mechanism maintains a fixed entrance and exit beam and is controlled by a single stepping motor; a simple mechanical linkage provides the additional motions which arc necessary to move the mirrors to the required positions. The novel features of this design are the simplicity of the mechanism and the use of narrow-band multilayer mirrors in place of crystal elements. Details of the design are presented as well as results of preliminary throughput and resolution tests using a pair of multilayer mirrors made to be particularly narrow band in order to be used in this type of instrument. © 1989 SPIE.