Results 31 to 40 of about 75 (57)

Stable method for the calculation of partition functions in the superconfiguration approach

Physical Review E, 2004
A general method for the calculation of the partition function of a canonical ensemble of noninteracting bound electrons is presented. It consists in a doubly recursive procedure with respect to the number of electrons and the number of orbitals. Contrary to existing approaches, this recursion relation contains no alternate summation of positive and ...
Franck, Gilleron, Jean-Christophe, Pain
openaire   +2 more sources

A superconfiguration code based on the local density approximation

Journal of Quantitative Spectroscopy and Radiative Transfer, 2000
Abstract The local density approximation (LDA) has been applied in a version of the SCO code based on the superconfiguration method. The self-consistent-field LDA equations for each superconfiguration are obtained by minimization of the free-energy functional with an appropriate number of constraints which guarantee the required populations of ...
T. Blenski, A. Grimaldi, F. Perrot
openaire   +1 more source

A superconfiguration calculation of opacity with consistent bound and continuum electron treatments using green’s functions

Journal of Physics B: Atomic, Molecular and Optical Physics, 2023
Abstract One of the challenges in calculating the opacity of dense plasmas is the difficulty in consistently modeling electrons bound to nuclei and those that exist within the continuum of free states in electronic structure models. We address this issue by adapting the green’s function approach, originally developed for use in average ...
N M Gill, C J Fontes, C E Starrett
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Further stable methods for the calculation of partition functions in the superconfiguration approach

Physical Review E, 2007
The extension to recursion over holes of the Gilleron and Pain method for calculating partition functions of a canonical ensemble of noninteracting bound electrons is presented as well as a generalization for the efficient computation of collisional line broadening.
Brian G, Wilson, Franck, Gilleron, Jean-Christophe, Pain   +2 more
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Model for computing superconfiguration temperatures in nonlocal-thermodynamic-equilibrium hot plasmas

Physical Review E, 2004
A model is presented where the level-population densities in quasi-steady-state hot dense plasmas are described by means of large nonrelativistic superconfigurations (SC's), whose configuration populations follow a decreasing-exponential law versus energy (Boltzmann like) for a temperature depending on the SC.
J, Bauche, C, Bauche-Arnoult, K B, Fournier   +2 more
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Operator technique for calculating superconfiguration-averaged quantities of atoms in plasmas

Physical Review E, 1997
An operator technique for performing superconfiguration averages is presented. This technique is applicable in the calculation of local thermodynamic equilibrium (LTE) spectral moments as well as average rates for the various atomic processes in non-LTE collisional radiative models.
J. Oreg, A. Bar-Shalom, M. Klapisch
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Quantum mechanical model for the study of pressure ionization in the superconfiguration approach

Journal of Physics A: Mathematical and General, 2006
The knowledge of plasma equation of state and photoabsorption requires suitable and realistic models for the description of ions. The number of relevant electronic configurations of ions in hot dense plasmas can be immense (increasing with atomic number Z).
J C Pain, G Dejonghe, T Blenski
openaire   +1 more source

On the superconfiguration approach to model NLTE plasma emission

Journal of Quantitative Spectroscopy and Radiative Transfer, 2001
Abstract We discuss some aspects of the superconfiguration approach as applied to NLTE problems. The framework of this study is the AVERROES/TRANSPEC model developed for simulating non-LTE spectra. The model acts as a postprocessor to plasma hydrodynamics simulations.
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Self-consistent approach for the thermodynamics of ions in dense plasmas in the superconfiguration approximation

Journal of Quantitative Spectroscopy and Radiative Transfer, 2003
Abstract We propose a new thermodynamic approach to ions in dense plasmas taking into account the screening by free electrons. The ions in fundamental and excited states are represented by a group of superconfigurations. Each superconfiguration containing an integer number of bound electrons is totally screened by free electrons in a Wigner–Seitz (WS)
Jean-Christophe Pain, Thomas Blenski
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The effect of first order superconfiguration energies on the opacity of hot dense matter

High Energy Density Physics, 2015
Abstract We have recently completed developing a new super transition array (STA) code for calculating absorption and emission spectra of LTE plasmas. The code follows the theory of Bar-Shalom et al. with various improvements. In this work we focus on the first order correction for the Boltzmann populations for which traditional calculations can be ...
Menahem Krief, Alexander Feigel
openaire   +1 more source