Open AccessMeasurement of the coherent beam properties at the CoSAXS beamline
Author(s) -
Kahnt Maik,
Klementiev Konstantin,
Haghighat Vahid,
Weninger Clemens,
Plivelic Tomás S.,
Terry Ann E.,
Björling Alexander
Publication year - 2021
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s1600577521009140
Subject(s) - beamline , optics , coherence (philosophical gambling strategy) , physics , synchrotron , degree of coherence , scattering , synchrotron radiation , photon , speckle pattern , photon flux , coherence time , beam (structure) , laser , quantum mechanics
The CoSAXS beamline at the MAX IV Laboratory is a modern multi‐purpose (coherent) small‐angle X‐ray scattering (CoSAXS) instrument, designed to provide intense and optionally coherent illumination at the sample position, enabling coherent imaging and speckle contrast techniques. X‐ray tracing simulations used to design the beamline optics have predicted a total photon flux of 10 12 –10 13 photons s −1 and a degree of coherence of up to 10% at 7.1 keV. The normalized degree of coherence and the coherent flux of this instrument were experimentally determined using the separability of a ptychographic reconstruction into multiple mutually incoherent modes and thus the Co herence in the name Co SAXS was verified. How the beamline can be used both for coherent imaging and XPCS measurements, which both heavily rely on the degree of coherence of the beam, was demonstrated. These results are the first experimental quantification of coherence properties in a SAXS instrument at a fourth‐generation synchrotron light source.