Spatial coherence of synchrotron radiation degraded by grating monochromators

TL;DR

This paper provides a theoretical analysis of how grating monochromators at synchrotrons degrade the spatial coherence of X-ray beams, highlighting the effects of grating parameters and propagation conditions.

Contribution

It offers a comprehensive physical and mathematical framework for understanding spatial coherence degradation caused by gratings in synchrotron radiation.

Findings

Degradation depends on grating parameters and focusing conditions

Theoretical model describes coherence loss starting from a fully coherent source

Analysis aids in optimizing monochromator design for better coherence

Abstract

In this work, we present a physical and theoretical description of the significant degradation of X-ray spatial coherence properties due to the use of grating monochromators at synchrotron facilities. We present a comprehensive study of the effects of spatial coherence degradation as a function of grating parameters under different focusing and propagation conditions. The focus is on the effect of spatial coherence degradation caused by the grating alone, starting from a fully coherent incident photon beam generated by a filament source. The mathematical description and theoretical analysis of the spatial coherence degradation is presented in the framework of statistical optics.