Dispersive spread of virtual sources by asymmetric X-ray monochromators

The principles of the virtual source spread (spatial broadening) phenomenon induced by angular dispersion in asymmetric X‐ray Bragg reflections are illustrated, from which the virtual source properties are analyzed for typical high‐resolution multiple‐crystal monochromators, including inline four‐bo...

Full description

Saved in:
Bibliographic Details
Published in:Journal of applied crystallography 2012-04, Vol.45 (2), p.255-262
Main Authors: Huang, X. R., Macrander, A. T., Honnicke, M. G., Cai, Y. Q., Fernandez, Patricia
Format: Article
Language:English
Subjects:
Asymmetry
Beams (radiation)
Crystallography
Dispersion
Dispersions
inelastic X-ray scattering
Monochromators
Nanostructure
Spectroscopy
Spreads
virtual sources
X-ray focusing
X-ray optics
X-rays
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The principles of the virtual source spread (spatial broadening) phenomenon induced by angular dispersion in asymmetric X‐ray Bragg reflections are illustrated, from which the virtual source properties are analyzed for typical high‐resolution multiple‐crystal monochromators, including inline four‐bounce dispersive monochromators, back‐reflection‐dispersion monochromators and nondispersive nested channel‐cut monochromators. It is found that dispersive monochromators can produce spread virtual sources of a few millimetres in size, which may prevent efficient microfocusing of the beam as required by inelastic X‐ray scattering spectroscopy and other applications. Possible schemes to mitigate this problem are discussed. The analyses may provide important guidelines for designing and optimizing modern high‐precision synchrotron X‐ray optics and beamline instrumentation for spectroscopy, imaging and nanofocusing applications.
ISSN:1600-5767
0021-8898
1600-5767
DOI:10.1107/S0021889812003366