A comparison between detailed and configurationaveraged collisionalradiative codes applied to nonlocal thermal equilibrium plasmas
Abstract
A collisionalradiative model describing nonlocalthermodynamicequilibrium plasmas is developed. It is based on the HULLAC (Hebrew University Lawrence Livermore Atomic Code) suite for the transitions rates, in the zerotemperature radiation field hypothesis. Two variants of the model are presented: the first one is configuration averaged, while the second one is a detailed level version. Comparisons are made between them in the case of a carbon plasma; they show that the configurationaveraged code gives correct results for an electronic temperature T{sub e}=10 eV (or higher) but fails at lower temperatures such as T{sub e}=1 eV. The validity of the configurationaveraged approximation is discussed: the intuitive criterion requiring that the average configurationenergy dispersion must be less than the electron thermal energy turns out to be a necessary but far from sufficient condition. Another condition based on the resolution of a modified rateequation system is proposed. Its efficiency is emphasized in the case of lowtemperature plasmas. Finally, it is shown that nearthreshold autoionization cascade processes may induce a severe failure of the configurationaverage formalism.
 Authors:
 Commissariat a l'Energie Atomique, Service 'Photons, Atomes et Molecules', Centre d'Etudes de Saclay, F91191 GifsurYvette Cedex (France)
 Publication Date:
 OSTI Identifier:
 20982753
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Journal of Applied Physics; Journal Volume: 101; Journal Issue: 6; Other Information: DOI: 10.1063/1.2713085; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; APPROXIMATIONS; AUTOIONIZATION; CARBON; COMPARATIVE EVALUATIONS; ELECTRON TEMPERATURE; ELECTRONS; EQUILIBRIUM PLASMA; EV RANGE 0110; ION TEMPERATURE; REACTION KINETICS; THERMAL EQUILIBRIUM; THERMODYNAMICS
Citation Formats
Poirier, M., and Gaufridy de Dortan, F. de. A comparison between detailed and configurationaveraged collisionalradiative codes applied to nonlocal thermal equilibrium plasmas. United States: N. p., 2007.
Web. doi:10.1063/1.2713085.
Poirier, M., & Gaufridy de Dortan, F. de. A comparison between detailed and configurationaveraged collisionalradiative codes applied to nonlocal thermal equilibrium plasmas. United States. doi:10.1063/1.2713085.
Poirier, M., and Gaufridy de Dortan, F. de. Thu .
"A comparison between detailed and configurationaveraged collisionalradiative codes applied to nonlocal thermal equilibrium plasmas". United States.
doi:10.1063/1.2713085.
@article{osti_20982753,
title = {A comparison between detailed and configurationaveraged collisionalradiative codes applied to nonlocal thermal equilibrium plasmas},
author = {Poirier, M. and Gaufridy de Dortan, F. de},
abstractNote = {A collisionalradiative model describing nonlocalthermodynamicequilibrium plasmas is developed. It is based on the HULLAC (Hebrew University Lawrence Livermore Atomic Code) suite for the transitions rates, in the zerotemperature radiation field hypothesis. Two variants of the model are presented: the first one is configuration averaged, while the second one is a detailed level version. Comparisons are made between them in the case of a carbon plasma; they show that the configurationaveraged code gives correct results for an electronic temperature T{sub e}=10 eV (or higher) but fails at lower temperatures such as T{sub e}=1 eV. The validity of the configurationaveraged approximation is discussed: the intuitive criterion requiring that the average configurationenergy dispersion must be less than the electron thermal energy turns out to be a necessary but far from sufficient condition. Another condition based on the resolution of a modified rateequation system is proposed. Its efficiency is emphasized in the case of lowtemperature plasmas. Finally, it is shown that nearthreshold autoionization cascade processes may induce a severe failure of the configurationaverage formalism.},
doi = {10.1063/1.2713085},
journal = {Journal of Applied Physics},
number = 6,
volume = 101,
place = {United States},
year = {Thu Mar 15 00:00:00 EDT 2007},
month = {Thu Mar 15 00:00:00 EDT 2007}
}

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