Prototype grooved and spherically bent Si backscattering crystal analyzer for meV resolution inelastic x-ray scattering

The effects of slope errors on a typical analyzer design with ray tracing were examined to make sure that there were no unforeseen geometrical problems that were limiting the resolution or efficiency. In addition, it was determined that grooved, spherically bent analyzer crystals should have excellent efficiency and energy resolution if the rms slope errors were maintained below 100 μrad. Measurements of the slope error and 1:1 focus size of a grooved (1,1,1)-oriented Si wafer in a proof-of-principle vacuum chuck bender provided rms slope errors less than 100 μrad and FWHM spot sizes of two millimeters. Thus, a high-efficiency, meV resolution analyzer should be entirely feasible.