ISSN:
1600-5767
Source:
Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Topics:
Geosciences
,
Physics
Notes:
The k-space resolution function of a new triple-crystal diffractometer for high-energy synchrotron radiation is calculated for an arrangement of three perfect silicon crystals diffracting in dispersive Laue geometry. A comparison is made with the results of measurements using 100 keV synchrotron radiation. The settings ({\bar 2} {\bar 2}0, 111, {\bar 2} {\bar 2}0) and ({\bar 2} {\bar 2}0, 400, {\bar 2} {\bar 2}0) are discussed in detail. All features of the measured resolution function are well reproduced by the calculations, especially if the background due to non-Bragg scattering from the collimators and the crystals is taken into account. In addition, approximate formulas are presented that provide a quick survey over the features of the resolution in k space for a given experimental set-up. On the 50% contour level, the λ streak is by far the dominating feature of the resolution function and reduces the resolution parallel to Gsample by a factor of 40 to about 8 × 10−3 Å−1. The excellent resolution in the scattering plane perpendicular to Gsample of 10−5 Å−1 is not affected. Unlike in the nondispersive case and diffraction experiments using characteristic lines of X-ray tubes, here the location and the intensity distribution of the monochromator streak depend on the Bragg angles of the monochromator, sample and analyzer crystal.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1107/S0021889895005516
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