An X-ray spectrometer for inelastic scattering experiments. I. Curved-crystal X-ray optics

The design parameters of an X-ray spectrometer for inelastic scattering studies are discussed, and a comparison is made of the flux available from various photon sources in the X-ray region. It is shown that a conventional X-ray sealed tube can yield a relatively high useful flux, provided monochromatic characteristic radiation over a large solid angle can be collected and focused on the target. A detailed theoretical study is presented of the reflectivity of elastically curved crystals of quartz, silicon and germanium for Cu Kα and Mo Kα radiation. A phase-space approach to X-ray optics proves to be very useful in evaluating the influence of the many geometrical factors. We show how these results can be used to optimize the performance of focusing X-ray optical components.