Focusing W Kα1 with a Curved Si Crystal

Abstract

The design, construction and operation of toroidal focusing X-ray monochromators have been described in detail by Marcus, et al. (1980) and by Furnas, et al. (1982), Marcus, et al. used 100 mechanically damaged, singly bent LiF (200) (2d = 4.02 Å) single crystals in a toroidal array to focus Cu Kα characteristic X-rays (8.04 keV, 1.54 Å, Θ = 22.6 deg). The diameter of the LiF toroid was 166 mm and the source-detector distance was 400 mm. Furnas, et al. used a series of singly bent, highly oriented graphite (2d = 6.72 Å) crystals, also in a toroidal array, to focus Pb Lα, Se Kα, Th Lα and U Lα X-rays (10.5 - 13.6 keV, 1.18 - 0.91 Å, Θ= 10.1 - 7.8 deg). Their system dimensions were not disclosed. The LiF and graphite crystals were both curved along the direction of X-ray propagation. That is, the cylindrical axes were orthogonal to the X-ray path.