
[Time resolved plasma spectroscopy of imploded gas-filled microballoons: The next generation]. Final technical report, 17 April 1995--30 September 1997
Author(s) -
C.F. Jr. Hooper
Publication year - 1998
Language(s) - English
Resource type - Reports
DOI - 10.2172/663263
Subject(s) - plasma , atomic physics , ion , radiative transfer , implosion , physics , spectral line , neon , opacity , argon , spectroscopy , plasma diagnostics , nuclear physics , optics , quantum mechanics , astronomy
This report is comprised of three documents which deal with plasma spectroscopy of laser-produced plasmas. In Appendix A the authors present a discussion of plasma line broadening with emphasis on the effects of accounting for ion-dynamic corrections. For two decades, high power lasers have been used to implode microballoons filled with gases such as neon, argon, deuterium, or mixtures of deuterium and argon. These implosions have generated high-temperature ({approx} 1 keV) and high density ({approx} 10{sup 23}/cc--10{sup 25}/cc) plasmas. As a result of these experiments, the authors are able to observe the radiative properties of highly charged ions in the presence of a variety of strongly coupled plasmas. Spectral radiation observed from these experiments is frequently in the x-ray region and the radiative properties are greatly influenced by plasma effects. In section 2 of this paper the authors discuss the theoretical techniques employed to interpret these spectra and describe two sets of implosion experiments. In section 3 they list some conclusions. Appendix B presents more research related to ion-dynamic corrections. The authors examine the combined effects of ion dynamics and opacity on line profiles used in the analysis of hot dense plasmas. Specifically, they have calculated Stark broadened line profiles for both resonance and satellite lines in highly stripped Ar ions, both in the quasi-static ion approximation, and including the effects of ion dynamics. Using the results of an NLTE kinetics code, combined with an escape factor formalism to account for the effects of radiative transfer, they have calculated the relative intensities of these lines, as well as the effects of opacity on their profiles. This model spectra is used in the analysis of experimental data. In a series of experiments performed at the Laboratory for Laser Energetics plastic microballoons filled with DD and doped with Ar were imploded using the Omega laser system. Here, the authors use time-resolved K-shell Ar spectra from the implosions. Varying the relative concentration of Ar in DD provides an opportunity to study the combined and individual effects of ion motion and opacity on the Stark broadened line profiles. Appendix C addresses the use of high opacity Krypton lines to diagnose high temperature implosions, and provides additional detail about the effects of ion dynamics