Wavelength-dispersive double flat-crystal analyzer for inelastic X-ray scattering

Abstract

A double¯at-crystal analyzer for inelastic X-ray scattering is described. The general correlation between the energy and direction of the X-rays transmitted by the analyzer allows one to collect data for a range of energy transfers simultaneously. Such an analyzer with 120 meV resolution was built to operate at the copper K edge. Experimental results show that this X-ray optic can be an alternative to a conventional spherical-focusing backscattering analyzer in resonant inelastic X-ray scattering experiments or when¯exible energy resolution or high momentum resolution is required.

Crystal monochromator with a resolution beyond 108

“…The horizontal angle±energy dispersion shown in Fig. 3 is signi®cant for sources that are widely divergent in a plane that is perpendicular to the diffraction plane (Bortel et al, 2000). For incident radiation that is highly collimated in the horizontal plane (42 mrad for the source used here), there is negligible change in the resolution function from the zero-horizontaldivergence limit.…”

Improving the performance of high-resolution X-ray spectrometers with position-sensitive pixel detectors

“…Inelastic X-ray scattering spectrometers utilizing dispersion-compensation methods (Berthold et al, 1992;Suortti et al, 2001) and PSDs (Bortel et al, 2000;Tohji & Udagawa, 1987) have also been constructed earlier. Most interesting is perhaps the spectrometer of Hä mä lä inen et al (1995), where a cylindrically bent crystal was used instead of a spherical diced analyzer, and the utilized non-dispersive geometry corresponds to the use of the cube surface as an energy-analyzing element in the present experiment.…”

Feasibility of in-line instruments for high-resolution inelastic X-ray scattering

“…The remaining discussion in this section will revolve around the consequences of divergence perpendicular to the scattering plane (horizontal). A previous study showed (Bortel et al, 2000) that the transmitted energy E for rays having an angle # out of the principal diffraction plane is given by…”

“…Studies have therefore investigated the use of materials such as sapphire (Yavas et al, 2007) or quartz (Sutter et al, 2006) instead, but the poorer crystal quality of such materials has so far prevented their use in high-resolution instruments. Bortel et al (2000) realised the possibility of replacing the spherically bent backscattering analyzer with a high-resolution monochromator using two flat asymmetrically cut silicon crystals. Their device provided an energy resolution of 89 meV at an operating energy of 8.979 keV.…”

“…In this paper we explore how the addition of achromatic focusing and collimating elements could improve the design of Bortel et al (2000) and produce a practical IXS instrument as envisioned earlier (Shvydko, 2004). We will call this concept the 'M 4 instrument' (derived from the monochromatormirror-mirror-monochromator arrangement), which is illustrated schematically in Fig.…”