Simple, constant length Rowland circle monochromators for undulator radiation

Abstract

Three new designs of spherical grating monochromators with constant length for the soft x-ray energy range for an undulator beamline are proposed. The principle and the optimization are described, as well as the fact why these monochromator types can still be considered as Rowland circle monochromators. Depending on the design a maximum resolving power between 13 000 and 40 000 is achievable. The calculations are in good agreement with ray trace results. The ray tracing was performed including source size and depth, slope errors as well as finite element analysis results for the preoptics.