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Title: K{sub α} x-ray imaging of laser-irradiated, limited-mass zirconium foils

X-ray fluorescence measurements to determine the effect of target heating on imaging efficiency, at a photon energy of 15.7 keV corresponding to the K{sub α} line of zirconium, have been carried out using limited-mass foils irradiated by the Texas Petawatt Laser. Zirconium foils that ranged in volume from 3000 × 3000 × 21 μm{sup 3} to 150 × 150 × 6 μm{sup 3} were irradiated with 100 J, 8 ps-long pulses and a mean intensity of 4 × 10{sup 19} W/cm{sup 2}. The K{sub α} emission was measured simultaneously using a highly ordered pyrolytic graphite crystal spectrometer and a curved quartz imaging crystal. The measured ratio of the integrated image signal to the integrated spectral signal was, within the experimental error, constant, indicating that the imaging efficiency's dependence on temperature is weak throughout the probed range. Based on our experience of target heating under similar conditions, we estimate a temperature of ∼200 eV for the smallest targets. The successful imaging of K{sub α} emission for temperatures this high represents an important proof of concept for Zr K{sub α} imaging. At these temperatures, the imaging of K{sub α} emission from lower-Z materials (such as Cu) is limited by temperature-dependent shifts in the K{sub α} emission energy.
Authors:
; ; ; ;  [1] ; ; ; ; ;  [2] ; ;  [3] ;  [4]
  1. Department of Physics, The Ohio State University, 191 West Woodruff Road, Columbus, Ohio 43210 (United States)
  2. The Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States)
  3. The Texas Center of High Energy Density Science, The University of Texas at Austin, 2511 Speedway Street, Austin, Texas 78712 (United States)
  4. General Atomics, 3550 General Atomics Court, San Diego, California 92121-1200 (United States)
Publication Date:
OSTI Identifier:
22304093
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 21; Journal Issue: 7; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; FLUORESCENCE; FOILS; GRAPHITE; HEATING; IRRADIATION; LASERS; MASS; PETAWATT POWER RANGE; TEMPERATURE DEPENDENCE; X RADIATION; ZIRCONIUM