X-Ray Bragg Diffraction in Asymmetric Backscattering Geometry
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
We observe three effects in the Bragg diffraction of x rays in backscattering geometry from asymmetrically cut crystals. First, exact Bragg backscattering takes place not at normal incidence to the reflecting atomic planes. Second, a well-collimated ({approx_equal}1 {mu}rad) beam is transformed after the Bragg reflection into a strongly divergent beam (230 {mu}rad) with reflection angle dependent on x-ray wavelength--an effect of angular dispersion. The asymmetrically cut crystal thus behaves like an optical prism, dispersing an incident collimated polychromatic beam. The dispersion rate is {approx_equal}8.5 mrad/eV. Third, parasitic Bragg reflections accompanying Bragg backreflection are suppressed. These effects offer a radically new means for monochromatization of x rays not limited by the intrinsic width of the Bragg reflection.
- OSTI ID:
- 20861459
- Journal Information:
- Physical Review Letters, Vol. 97, Issue 23; Other Information: DOI: 10.1103/PhysRevLett.97.235502; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0031-9007
- Country of Publication:
- United States
- Language:
- English
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