Crystal optics as guard apertures for coherent x-ray diffraction imaging.
A crucial issue in coherent x-ray diffraction imaging experiments is how to increase the signal-to-noise ratio when measuring relatively weak diffraction intensities from a nonperiodic object. A novel crystal guard aperture is described that makes use of a pair of multiple-bounce crystal optics to eliminate unwanted parasitic scattering background. This background is often produced by upstream optical elements such as a coherent-beam defining aperture. Recent experimental observation and theoretical analysis confirm the effectiveness of the crystal guard aperture method with coherence-preserved wave propagation through the crystal guard aperture and dramatically reduced scattering background in coherent x-ray diffraction images.
Xiao
Xianghui
X
Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA. xhxiao@aps.anl.gov
de Jonge
Martin D
MD
Zhong
Yuncheng
Y
Chu
Yong S
YS
Shen
Qun
Q