Investigation of `glitches' in the energy spectrum induced by single-crystal diamond compound X-ray refractive lenses

Abstract

Single‐crystal diamond stands out among all the candidate materials that could be exploited to fabricate compound refractive lenses (CRLs) owing to its extremely stable properties. Among all related experimental features, beam divergence, χ‐angles relative to the incoming beam in Eulerian geometry and different positions of the X‐ray beam relative to the lens geometry may influence the transmission energy spectrum of CRLs. In addition, the orientation of the single‐crystal diamond sample may also affect the glitches significantly. To verify these initial assumptions, two experiments, an energy scan and an ω‐scan, were set up by employing a polished diamond plate consisting of five biconcave lenses. The results show that beam divergence does not affect the spectrum, nor do χ‐angles when ω is set to zero. Nevertheless, different incident positions have an appreciable effect on the transmission spectrum, in particular the `strengths' of the glitches. This is attributed to absorption. The ω‐scan setup is capable of determining the so‐called orientation matrix, which may be used to predict both `energy positions' and `strengths' of the glitches.

Full-field neutron microscopy based on refractive optics

“…In that connection, a better understanding of the requirement with regard to crystallinity is needed. Polycrystalline lenses with large grains will lead to glitches in the spectrum (Zhang et al, 2019), while nanocrystalline grains will lead to massive secondary extinction and consequently an orders-of-magnitude increase in the effective attenuation. The acceptable range needs to be determined.…”

Suppressing Diffraction-Related Intensity Losses in Transmissive Single-Crystal X-ray Optics

“…The sample was mounted at a three-cradle goniometer so it could be rotated around any axis during the measurements. More details about the samples and the experiment can be found in [22,23]. detector, one can derive the glitches' influence from the spatial distribution of the beam at the 2D detector [14,15].…”

“…The sample was mounted at a three-cradle goniometer so it could be rotated around any axis during the measurements. More details about the samples and the experiment can be found in [22,23]. For the first CRL (which we refer to as MUL) [19], we launched several scans at different angles χ (rotation around the beam-see Figure 1).…”

Using diffraction losses of X-rays in a single crystal for determination of its lattice parameters as well as for monochromator calibration

“…Nevertheless, we have found a way to use this drawback of single-crystal optics. In the present paper, we analyse the spectra measured previously (Polikarpov et al, 2018;Zhang et al, 2019) and we show that by careful analysis of glitches the unit-cell (UC) parameters of crystalline optics, used in transmission geometry, can be accurately determined. Usually, the UC parameters are determined from some diffraction experiments with X-rays or electrons -for a rather complete and recent review of the methods used for UC parameter determination see Lider (2020).…”

“…However, we should note one drawback of X-ray optics made of single crystals -intensity modulation at certain energies in the transmission spectrum. This issue is termed 'diffraction loss' or the 'glitch effect' (Polikarpov et al, 2018;Zhang et al, 2019). The effect manifests itself as follows: at some energy of the X-rays, the transmitted (or diffracted in the case of monochromators) beam intensity drops.…”