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Title: High-resolution spectroscopic diagnostics of very high-temperature plasmas in the hard x-ray regime

Thesis/Dissertation ·
DOI:https://doi.org/10.2172/15013111· OSTI ID:15013111
 [1]
  1. Graz Univ. of Technology (Austria)

Motivated by the need for establishing a reliable database useful for the application of x-ray spectroscopic tools for the diagnostic of very high temperature plasmas, high-resolution crystal spectrometer measurements have been performed investigating the characteristic K-shell radiation of highly charged krypton and xenon. The measurements, which have been performed at the Electron-Beam-Ion-Trap (EBIT) facility of the Lawrence Livermore National Laboratory, include the investigation of the n = 2 → 1 transitions in heliumlike krypton (Kr34+) and innershell excited lithiumlike krypton (Kr{sup 33+}) utilizing a conventional reflection-type crystal spectrometer of von Hamos geometry. The electron-excitation-energy selective measurements map the contribution of the dielectronic recombination lines providing the means of accurate interpretation of the line profiles of the characteristic Kα x-ray emission of plasmas. The high-resolution measurements of the n = 2 → 1 transitions in heliumlike xenon (Xe52+) and hydrogenlike xenon (Xe53+) were based on a new transmission-type crystal spectrometer of DuMond geometry. The resolving power of the developed spectrometer was sufficient for charge state specific observation allowing the determination of the electron-impact excitation cross section for the hydrogen- and heliumlike Kα transitions. The disagreement with theoretically predicted values is a measure of the magnitude of the Breit interaction for the highly charged high-Z ions.

Research Organization:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Organization:
USDOE
DOE Contract Number:
W-7405-ENG-48
OSTI ID:
15013111
Report Number(s):
UCRL-LR-136955; TRN: US0600875
Country of Publication:
United States
Language:
English