Reflection efficiency and spectra resolutions ray-tracing simulations for the VOXES HAPG crystal based Von Hamos spectrometer

TL;DR

This paper presents ray-tracing simulations and experimental validation of the reflection efficiency and spectral resolution of a HAPG crystal-based Von Hamos X-ray spectrometer, demonstrating its high precision and potential applications.

Contribution

It introduces detailed simulation procedures and compares them with experimental results to evaluate the spectrometer's efficiency and resolution, advancing understanding of its performance.

Findings

Reflection efficiency characterized for Cu and Fe Kα lines

Simulation results agree with experimental data

Spectrometer achieves sub-10 eV resolution

Abstract

The VOXES collaboration at INFN National Laboratories of Frascati developed a prototype of a high resolution Von Hamos X-ray spectrometer using HAPG (Highly Annealed Pyrolytic Graphite) mosaic crystals. This technology allows the employment of extended isotropic sources and could find application in several physics fields. The capability of the spectrometer to reach energy precision and resolution below 1 and 10 eV, respectively, when used with wide sources have been already demonstrated. Recently, the response of this device, for a $\rho$ = 206.7 mm cylindrically bent HAPG crystal using $CuK\alpha_{1,2}$ and $FeK\alpha_{1,2}$ XRF lines, has been investigated in terms of reflection efficiency by a dedicated ray-tracing simulation. Details of the simulation procedure and the comparison with the experimental results are presented. This study is crucial in order to retrieve information on the spectrometer signal collection efficiency, especially in the energy range in which the standard calibration procedures cannot be applied.