Development of a high resolution x-ray spectrometer for the National Ignition Facility (NIF)

A high resolution (E/ ΔE = 1200-1800) Bragg crystalx-ray spectrometer is being developed tomeasureplasma parameters in National Ignition Facility experiments. The instrument will be adiagnostic instrument manipulator positioned cassette designed mainly to infer electron density in compressed capsules from Stark broadening of the helium- β (1s2-1s3p) lines of krypton and electron temperature from the relative intensities of dielectronic satellites. Two conically shaped crystals willdiffract and focus (1) the Kr He β complex and (2) the Heα (1s2-1s2p) and Ly α (1s-2p) complexes onto a streakcameraphotocathode fortime resolvedmeasurement, and a third cylindrical or conical crystal will focus the full He α to Heβ spectral range onto an image plate to provide a time integrated calibration spectrum. Calculations of sourcex-ray intensity,spectrometer throughput, and spectral resolution are presented. Details of the conical-crystal focusing properties as well as the status of the instrumental design are also presented.

Source: Review of Scientific Instruments - September 28, 2016 Category: Physics Authors: K. W. Hill, M. Bitter, L. Delgado-Aparicio, P. C. Efthimion, R. Ellis, L. Gao, J. Maddox, N. A. Pablant, M. B. Schneider, H. Chen, S. Ayers, R. L. Kauffman, A. G. MacPhee, P. Beiersdorfer, R. Bettencourt, T. Ma, R. C. Nora, H. A. Scott, D. B. Thorn, J. D. Source Type: research