Coherence properties from speckle contrast analysis at the European XFEL. Issue 1 (1st December 2022)

• Record Type: Journal Article
• Authors: Dallari, F; Lokteva, I; Möller, J; Jain, A; Roseker, W; Westermeier, F; Goy, C; Boesenberg, U; Hallmann, J; Rodriguez-Fernandez, A; Scholz, M; Shayduk, R; Madsen, A; Grübel, G; Lehmkühler, F
• Is Part Of: Journal of physics. Volume 2380 Issue 1(2022)
• Publication Date: 2022-12-01
• Subjects: Physics -- Congresses; 530.5
• DOI: 10.1088/1742-6596/2380/1/012085
• Languages: English
• ISSNs: 1742-6588

Abstract

Abstract: We show the results of speckle contrast analysis at the MID instrument of European XFEL in the hard X-ray regime. Speckle patterns measured from static colloidal samples are compared to results previously obtained at the SPB/SFX instrument. A high degree of coherence of 0.79 is obtained by modelling the q -dependence of the speckle contrast, that corresponds to a number of coherent modes of M = 1.7. Furthermore, the variation of contrast over many pulse trains is exceptional low, resulting in a degree of coherence with a relative standard deviation below 0.1. Our results demonstrate the high stability of coherence properties at European XFEL over many X-ray pulses and pulse trains which is a prerequisite for coherence-based techniques such as MHz X-ray photon correlation spectroscopy.