Hybrid diamond-silicon angular-dispersive x-ray monochromator with 0.25-meV energy bandwidth and high spectral efficiency

作者：Stoupin S^*; Shvyd'ko Y V; Shu D; Blank V D; Terentyev S A; Polyakov S N; Kuznetsov M S; Lemesh I; Mundboth K; Collins S P; Sutter J P; Tolkiehn M

来源：Optics Express, 2013, 21(25): 30932-30946.

DOI：10.1364/OE.21.030932

We report on the design, implementation, and performance of an x-ray monochromator with ultra-high energy resolution (Delta E/E similar or equal to 2.7 x 10(-8)) and high spectral efficiency using x rays with photon energies E similar or equal to 9.13 keV. The operating principle of the monochromator is based on the phenomenon of angular dispersion in Bragg back-diffraction. The optical scheme of the monochromator is a modification of a scheme reported earlier [Shvyd'ko et al., Phys. Rev. A 84, 053823 (2011)], where a collimator/wavelength selector Si crystal was replaced with a 100-m m-thick type IIa diamond crystal. This modification provides a very-small-energy bandwidth Delta E similar or equal to 0.25 meV, a 3-fold increase in the aperture of the accepted beam, a reduction in the cumulative angular dispersion rate of x rays emanating from the monochromator for better focusing on a sample, a sufficient angular acceptance matching the angular divergence of an undulator source (approximate to 10 mu rad), and an improved throughput due to low x-ray absorption in the thin diamond crystal. The measured spectral efficiency of the monochromator was approximate to 65% with an aperture of 0.3 x 1 mm(2). The performance parameters of the monochromator are suitable for inelastic x-ray spectroscopy with an absolute energy resolution Delta E < 1 meV.

• 出版日期2013-12-16