Measurement of the Spatial Coherence Function of Undulator Radiation using a Phase Mask

Abstract

A measurement of the horizontal coherence function of 7.9 keV radiation from an undulator beam line at the Advanced Photon Source is reported. X-ray diffraction from a phase-shifting mask was used, and the coherence function was measured as a function of the width of beam-conditioning slits in the beam line. The coherence distribution is found to be best described by a Lorentzian function.

Modelling of partially coherent radiation based on the coherent mode decomposition

“…In this case the spectral degree of coherence cannot be described by a single Gaussian function (compare to results of Ref. [23]). However, we should note here that these separations are much larger than the beam size and will be difficult to access in a real experiment.…”

Measurement of hard X-ray coherence in the presence of a rotating random-phase-screen diffuser

“…[16]). Another important method for coherence measurement makes use of a uniformly redundant array (URA), as a complex phase mask which diffracts the incident beam equivalently to the parallelized superposition of multiple Young's experiments [23].…”

Measurement of the spatial coherence of hard synchrotron radiation using a pencil beam

“…Another grating-based technique characterizes hard x ray transverse coherence properties by estimating the intensity profile of a diffraction pattern in which the Gaussian-Schell model (GSM) is used in an iterative phase retrieval procedure [21] . Similarly, a uniformly redundant array [22] and a nonredundant array [23] have also been used to acquire spatial coherence by the deconvolution of measured diffraction patterns.…”