A Short Working Distance Multiple Crystal X-ray Spectrometer

TL;DR

This paper introduces a compact, short working distance multicrystal X-ray spectrometer that achieves high energy resolution and large collection angles, enabling efficient measurements at small sample sizes and high-brightness sources.

Contribution

The development and testing of a novel short working distance multicrystal X-ray spectrometer with a large collection solid angle and high resolution, suitable for advanced light source applications.

Findings

Achieved a maximum collection solid angle of 0.14 sr

Demonstrated accurate measurements of Mn K_beta X-ray emission and RIXS

Validated performance with measurements on MnO and Dy metal samples

Abstract

For x-ray spot sizes of a few tens of microns or smaller, a mm-sized flat analyzer crystal placed ~ 1 cm from the sample will exhibit high energy resolution while subtending a collection solid angle comparable to that of a typical spherically bent crystal analyzer (SBCA) at much larger working distances. Based on this observation and a non-focusing geometry for the analyzer optic, we have constructed and tested a short working distance (SWD) multicrystal x-ray spectrometer. This prototype instrument has a maximum effective collection solid angle of 0.14 sr, comparable to that of 17 SBCA at 1 meter working distance. We find good agreement with prior work for measurements of the Mn K_beta x-ray emission and resonant inelastic x-ray scattering (RIXS) for MnO and also for measurements of the x-ray absorption near-edge structure for Dy metal using Lalpha2 partial-fluorescence yield detection. We discuss future applications at third- and fourth-generation light sources. For concentrated samples, the extremely large collection angle of SWD spectrometers will permit collection of high-resolution x-ray emission spectra with a single pulse of the Linac Coherent Light Source.