Investigation of the role of hot electrons in laser-produced plasma heating via simultaneous measurement of Cu K shell and L shell emissions

ORAL

Abstract

We investigate the heating of solid copper (Cu) targets by the second harmonic (527 nm) of the COMET Nd:Glass laser at Jupiter Laser Facility (JLF) at an intensity of I~1019 W/cm2. Using a Germanium-220 crystal, high-resolution (E/△E~5300) measurements of Cu Kα (7.9 - 8.6 keV) were obtained, and broadband measurements of 7.5 - 10 keV were achieved with moderate resolution (E/△E~2500) using a Von Hamos spectrometer. A Von Hamos-type L shell spectrometer measured emissions from 0.9 - 2 keV. The estimated Cu Kα conversion efficiency, based on K shell spectra from high-resolution and Von Hamos spectrometer, is order of 10-6 and increases with Cu thickness, reaching a saturation point after 3 μm thick Cu. The linewidth of Cu Kα1 emission was found to decrease with increasing Cu thickness. Plasma temperature and density are estimated using simultaneously measured L shell spectra. Together, these measurements from Cu K shell and L shell spectra provide a detailed description of HED plasmas generated by a relativistically-intense laser at 527 nm.

*This work is supported by the U.S. DOE Office of Science, Fusion Energy Sciences LaserNetUS initiative, and the Natural Sciences and Engineering Research Council of Canada (Grant No. RGPIN-2021-04373, Hussein). SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525. All opinions expressed in this presentation are the author's and do not necessarily reflect the policies and views of DOE.

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Presenters

  • Shubho Mohajan

    • Univ of Alberta

Authors

  • Shubho Mohajan

    • Univ of Alberta

  • Nick F Beier

    • University of Alberta

  • Danny Attiyah

    • University of California, Irvine

  • Carlton Kim

    • University of Alberta

  • Vigneshvar Senthilkumaran

    • University of Alberta

  • Christopher Gardner

    • University of California, Irvine

  • Austin M Linder

    • Lawrence Livermore National Laboratory

  • Lan Gao

    • PPPL
    • Princeton Plasma Physics Laboratory

  • Kenneth W Hill

    • PPPL
    • Princeton Plasma Physics Laboratory

  • Kirk A Flippo

    • Los Alamos Natl Lab

  • Stephanie B Hansen

    • Sandia National Laboratories
    • Sandia National Laboratory
    • Sandia Natl Lab

  • Ronnie L Shepherd

    • Lawrence Livermore Natl Lab

  • Franklin J Dollar

    • University of California, Irvine

  • Amina E Hussein

    • University of Alberta, Canada
    • Univ of Alberta