Crystal monochromator with a resolution beyond 10⁸

Abstract

Monochromatization with crystal diffraction has been achieved to a resolution (lambda/delta lambda) beyond 10(8). The monchromator is specifically designed for 23.880 keV synchrotron radiation (lambda = 51.9 pm) for applications involving nuclear resonant scattering from 119Sn. The design uses asymmetrically cut silicon (12 12 12) crystal reflections from two single-crystalline monoliths oriented in a dispersive geometry. A transmitted energy bandwidth of 140 +/- 20 mu eV was measured, corresponding to a resolution of 1.7 x 10(8). Methods of improving efficiency, wavelength stability and resolution are discussed.

Diffraction with a coherent X-ray beam: dynamics and imaging

“…The larger energy bandwidth is = ' 3 Â 10 À4 with the Ge (111) Bragg reflection (Hart & Berman, 1998). This bandwidth is reduced to ' 10 À8 in inelastic scattering beamlines (Verbeni et al, 1996;Toellner et al, 2001), which means that the longitudinal coherence lengths vary from the mm to the cm range.…”

Lattice dynamics in Sn nanoislands and cluster-assembled films

“…to detect possible deviations from the Debye behaviour. While this is currently not possible, developments are ongoing for improving the energy resolution towards the 100 µeV range 64,65 . A future challenge is to correlate the changes in the phonon density of states at the nanoscale to changes in the superconducting behaviour.…”

Using angular dispersion and anomalous transmission to shape ultramonochromatic x rays

“…This is an unusually large number. Typically, the angular acceptance of high-resolution x-ray monochromators is in a 10 to 20 µrad range, often requiring collimating optics, such that the x rays from the source to be fully accepted by the monochromator [2,[4][5][6][7][8][9]21]. The only exception to this rule are single bounce monochromators [22], which, however, have a disadvantage of long Lorentzian tails in the spectral resolution function.…”

“…The intrinsic Bragg bandwidth can be reduced [2][3][4][5][6][7][8][9] by using the so-called asymmetric x-ray diffraction, diffraction from atomic planes at nonzero angle η to the crystal face - Fig. 1.…”