학술논문
Quantifying electron temperature distributions from time-integrated x-ray emission spectra.
Document Type
Academic Journal
Author
MacDonald MJ; Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.; Liedahl DA; Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.; Brown GV; Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.; Åberg D; Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.; Cliche DT; Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.; Foord ME; Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.; Grabowski PE; Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.; Heeter RF; Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.; Hoarty DJ; Directorate of Research and Applied Science, AWE Plc, Reading RG7 4PR, United Kingdom.; London RA; Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.; Martin ME; Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.; Nilsen J; Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.; Patel MV; Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.; Scott HA; Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.; Shepherd R; Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.; Whitley HD; Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.; Widmann K; Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.
Source
Publisher: American Institute Of Physics Country of Publication: United States NLM ID: 0405571 Publication Model: Print Cited Medium: Internet ISSN: 1089-7623 (Electronic) Linking ISSN: 00346748 NLM ISO Abbreviation: Rev Sci Instrum Subsets: PubMed not MEDLINE; MEDLINE
Subject
Language
English
Abstract
K-shell x-ray emission spectroscopy is a standard tool used to diagnose the plasma conditions created in high-energy-density physics experiments. In the simplest approach, the emissivity-weighted average temperature of the plasma can be extracted by fitting an emission spectrum to a single temperature condition. It is known, however, that a range of plasma conditions can contribute to the measured spectra due to a combination of the evolution of the sample and spatial gradients. In this work, we define a parameterized model of the temperature distribution and use Markov Chain Monte Carlo sampling of the input parameters, yielding uncertainties in the fit parameters to assess the uniqueness of the inferred temperature distribution. We present the analysis of time-integrated S and Fe x-ray spectroscopic data from the Orion laser facility and demonstrate that while fitting each spectral region to a single temperature yields two different temperatures, both spectra can be fit simultaneously with a single temperature distribution. We find that fitting both spectral regions together requires a maximum temperature of 1310 -70 +90 eV with significant contributions from temperatures down to 200 eV.