All-diamond optical assemblies for a beam-multiplexing X-ray monochromator at the Linac Coherent Light Source

Abstract

All-diamond optical assemblies holding state-of-the-art type IIa diamond crystals enable the construction of a beam-multiplexing X-ray double-crystal monochromator for hard X-ray free-electron lasers. Details on the design, fabrication and X-ray diffraction characterization of the assemblies are reported.

Sequential x-ray diffraction topography at 1-BM x-ray optics testing beamline at the advanced photon source

“…This detector is constructed using an optical fiber bundle (1:1 fiberoptic ratio) coupled to a CCD with a pixel size of 13 μm. The signal-to-noise ratio was found to be excellent using exposure times 050020-2 of 0.5 -1 seconds per frame at an incident photon flux of 1×10 8 Hz/mm 2 in the studied higher order diffraction configuration (i.e., Si (531) -diamond (400)).…”

“…Under this condition the rocking curve width becomes directly comparable with the intrinsic width of the angular reflectivity curve given by the dynamical theory of X-ray diffraction. The width of the curve for perfect crystals can be calculated using suitable X-ray diffraction codes (e.g., [11]) and used for benchmarking the experimental results (e.g., [8]). The beam conditioners were fabricated in-house from high-resistivity float-zone-grown silicon crystals using the comprehensive fabrication equipment at the APS.…”

“…Furthermore, data collected at different azimuthal rotations around the sample surface normal can be used to decompose the maps of angular peak position into maps of the lattice parameter variation and lattice misorientations (e.g., [2,3]). Since its introduction, rocking curve imaging has been used to perform detailed characterization of semiconductor single crystals such as InP, SiC, GaAs [1,3,5] and single crystal diamond [2,6,7,8]. In particular, detailed characterization of single crystal diamond X-ray optics provided by the technique has been found valuable for implementation of novel diamond X-ray optics [7,8,9].…”

Performance of a beam-multiplexing diamond crystal monochromator at the Linac Coherent Light Source

“…More detail of the mounting and crystal characterization is beyond the scope of the current paper and is discussed extensively in Ref. 33. Section III of the paper will focus on the performance of the LODCM with C * (111) crystals.…”

Focusing of white synchrotron radiation using large-acceptance cylindrical refractive lenses made of single – crystal diamond

“…Indeed, when materials are thermomechanically ranked [7] by the figure-of-merit (κ/α, where κ is thermal conductivity and α is thermal-expansion coefficient), the κ/α for beryllium is ≈ 100 times worse than that of diamond at room temperature. Diamond, as the top heat-and radiation-resistant material has already shown excellent performance in diamond monochromators [7] and beam splitters [8]. Concerning the optical properties, diamond is a low-Z material and has an absorption which is tenfold worse than that of beryllium, whereas the refractive index is double of the beryllium, cutting by a factor of two the number of X-ray lenses in the experimental scheme.…”