Properties of Laser-Produced GaAs Plasmas Measured from Highly Resolved X-Ray Line Shapes and Ratios

Published

February 17, 2018

Author(s)

Lawrence T. Hudson, John F. Seely, J. Fein, P Keiffer, R.P. Drake, C.C. Kuranz, P Belancourt, Uri Feldman

Abstract

The properties of hot, dense plasmas generated by the irradiation of GaAs targets by the Titan laser at Lawrence Livermore National Laboratory were determined by the analysis of high resolution K shell spectra in the 9 keV to 11 keV range. The laser parameters, such as relatively long pulse duration and large focal spot, were chosen to produce a steady-state plasma with minimal edge gradients, and the time-integrated spectra were compared to non-LTE steady state spectrum simulations using the FLYCHK and NOMAD codes. The bulk plasma streaming velocity was measured from the energy shifts of the Ga He-like transitions and Li-like dielectronic satellites. The electron density and the electron energy distribution, both the thermal and the hot non-thermal components, were determined from the spectral line ratios. After accounting for the spectral line broadening contributions, the plasma turbulent motion was measured from the residual line widths. The ionization balance was determined from the ratios of the He-like through F-like spectral features. The detailed comparison of the experimental Ga spectrum and the spectrum simulated by the FLYCHK code indicates two significant discrepancies, the transition energy of a Li-like dielectronic satellite (designated t) and the calculated intensity of a He-like line (x), that should lead to improvements in the kinetics codes used to simulate the x-ray spectra from highly-charged ions

Citation

High Energy Density Physics

Volume

26

Pub Type

Journals

Download Paper

https://doi.org/10.1016/j.hedp.2018.02.002

Keywords

x-ray spectroscopy, plasma diagnostics, laser-produced plasmas, hard x-ray spectra

Citation

Hudson, L. , Seely, J. , Fein, J. , Keiffer, P. , Drake, R. , Kuranz, C. , Belancourt, P. and Feldman, U. (2018), Properties of Laser-Produced GaAs Plasmas Measured from Highly Resolved X-Ray Line Shapes and Ratios, High Energy Density Physics, [online], https://doi.org/10.1016/j.hedp.2018.02.002 (Accessed December 9, 2024)