Coherence Length and Vibrations of the Coherence Beamline I13 at the Diamond Light Source

X-Ray Microscopy Conference 2016

Wagner, U.H.^1 ; Parson, A.^1 ; Rau, C.^1,2

Diamond Light Source, Oxon, Chilton, Didcot

OX11 0DE, United Kingdom^1

Northwestern University, Chicago

IL

60611-3008, United States^2

关键词: Coherence lengths;    Coherent diffraction;    Diamond light source;    Fringe visibilities;    Mechanical design;    Optical components;    Photon counting detectors;    Thermal influence;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/849/1/012048/pdf
DOI  :  10.1088/1742-6596/849/1/012048

来源: IOP

【 摘 要 】

I13 is a 250 m long hard x-ray beamline for imaging and coherent diffraction at the Diamond Light Source. The beamline (6 keV to 35 keV) comprises two independent experimental endstations: one for imaging in direct space using x-ray microscopy and one for imaging in reciprocal space using coherent diffraction based imaging techniques [1]. In particular the coherence experiments pose very high demands on the performance on the beamline instrumentation, requiring extensive testing and optimisation of each component, even during the assembly phase. Various aspects like the quality of optical components, the mechanical design concept, vibrations, drifts, thermal influences and the performance of motion systems are of particular importance. In this paper we study the impact of the front-end slit size (FE slit size), which determines the horizontal source size, onto the coherence length and the detrimental impact of monochromator vibrations using in-situ x-ray metrology in conjunction with fringe visibility measurements and vibration measurements, based on centroid tracking of an x-ray pencil beam with a photon-counting detector.