title: Integrated x-ray reflectivity measurements of elliptically curved pentaerythritol crystals.
abstract: The elliptically curved pentaerythritol (PET) crystals used in the Supersnout 2 x-ray spectrometer on the National Ignition Facility at Lawrence Livermore National Laboratory have been calibrated photometrically in the range of 5.5-16 keV. The elliptical geometry provides broad spectral coverage and minimizes the degradation of spectral resolution due to the finite source size. The reflectivity curve of the crystals was measured using a x-ray line source. The integrated reflectivity (R(I)) and width of its curve (ΔΘ) were the measurements of major interest. The former gives the spectrometer throughput, and the latter gives the spectrometer resolving power. Both parameters are found to vary considerably with the radius of curvature of the crystal and with spectral energy. The results are attributed to an enhanced mosaic effect due to the increase in curvature. There are also contributions from the crystal cleaving and gluing processes.
authors.affiliation: National Security Technologies, LLC, Livermore, California 94551, USA. haughmj@nv.doe.gov
authors.forename: M J
authors.initials: MJ
authors.lastname: Haugh
authors.forename: S P
authors.initials: SP
authors.lastname: Regan
authors.forename: K D
authors.initials: KD
authors.lastname: Jacoby
authors.forename: P W
authors.initials: PW
authors.lastname: Ross
authors.forename: J
authors.initials: J
authors.lastname: Magoon
authors.forename: M A
authors.initials: MA
authors.lastname: Barrios
authors.forename: J A
authors.initials: JA
authors.lastname: Emig
authors.forename: M J
authors.initials: MJ
authors.lastname: Shoup
authors.forename: K B
authors.initials: KB
authors.lastname: Fournier