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Title: High temperature high density atomic environment and the Bremsstrahlung process

Abstract

This work is a study of atomic features of high temperature high density environments; the characteristics of the bremsstrahlung process from isolated atoms and ions; and the extent of modification of the features of the bremsstrahlung process in a high temperature high density environment. The average degree of ionization Z, energy levels, bound-free transitions and spectral line shifts from hot dense plasmas, as calculated within the Thomas-Fermi and the Debye-Huckel Thomas-Fermi statistical potentials have been studied. A useful parametrization has been obtained for the bremsstrahlung spectrum for all Z's in most ranges of incident electron energy, fraction of energy radiated, nuclear and ionic charge, utilizing one variable functions. The positron bremsstrahlung spectrum and the ratio between positron and electron spectra has been studied. The numerical results have been compared with predictions for the ratio of the two spectra from the nonrelativistic Sommerfeld formula (Coulomb case) or with a ratio of screened normalizations (screened case). The connection between bremsstrahlung tip and direct radiative recombination angular distributions and photon polarization correlations has been illustrated. The free-free Gaunt factors for hot dense Cs plasmas at varying temperatures and densities, using a full relativistic calculation with partial wave and multipole expansions in the TFmore » potential have been calculated. The usefulness of approximating the spectrum by that of an isolated ion (the ionic charge is determined by the average degree of ionization) is limited to not too high a density and away form the soft-photon end. Elwer-Born approximation is only valid at intermediate energies.« less

Authors:
Publication Date:
Research Org.:
Pittsburgh Univ., PA (USA)
OSTI Identifier:
5004591
Resource Type:
Thesis/Dissertation
Resource Relation:
Other Information: Thesis (Ph. D.)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; ELECTRON-ATOM COLLISIONS; BREMSSTRAHLUNG; ELECTRON-ION COLLISIONS; ANGULAR DISTRIBUTION; ATOMS; CESIUM; COMPARATIVE EVALUATIONS; DENSITY; ELECTRON SPECTRA; ENERGY LEVELS; HIGH TEMPERATURE; IONIZATION; IONS; PLASMA; POLARIZATION; POSITRONS; SPECTRAL SHIFT; ALKALI METALS; ANTILEPTONS; ANTIMATTER; ANTIPARTICLES; ATOM COLLISIONS; CHARGED PARTICLES; COLLISIONS; DISTRIBUTION; ELECTROMAGNETIC RADIATION; ELECTRON COLLISIONS; ELEMENTARY PARTICLES; ELEMENTS; FERMIONS; ION COLLISIONS; LEPTONS; METALS; PHYSICAL PROPERTIES; RADIATIONS; SPECTRA; 640304* - Atomic, Molecular & Chemical Physics- Collision Phenomena

Citation Formats

Feng, I J. High temperature high density atomic environment and the Bremsstrahlung process. United States: N. p., 1982. Web.
Feng, I J. High temperature high density atomic environment and the Bremsstrahlung process. United States.
Feng, I J. Fri . "High temperature high density atomic environment and the Bremsstrahlung process". United States.
@article{osti_5004591,
title = {High temperature high density atomic environment and the Bremsstrahlung process},
author = {Feng, I J},
abstractNote = {This work is a study of atomic features of high temperature high density environments; the characteristics of the bremsstrahlung process from isolated atoms and ions; and the extent of modification of the features of the bremsstrahlung process in a high temperature high density environment. The average degree of ionization Z, energy levels, bound-free transitions and spectral line shifts from hot dense plasmas, as calculated within the Thomas-Fermi and the Debye-Huckel Thomas-Fermi statistical potentials have been studied. A useful parametrization has been obtained for the bremsstrahlung spectrum for all Z's in most ranges of incident electron energy, fraction of energy radiated, nuclear and ionic charge, utilizing one variable functions. The positron bremsstrahlung spectrum and the ratio between positron and electron spectra has been studied. The numerical results have been compared with predictions for the ratio of the two spectra from the nonrelativistic Sommerfeld formula (Coulomb case) or with a ratio of screened normalizations (screened case). The connection between bremsstrahlung tip and direct radiative recombination angular distributions and photon polarization correlations has been illustrated. The free-free Gaunt factors for hot dense Cs plasmas at varying temperatures and densities, using a full relativistic calculation with partial wave and multipole expansions in the TF potential have been calculated. The usefulness of approximating the spectrum by that of an isolated ion (the ionic charge is determined by the average degree of ionization) is limited to not too high a density and away form the soft-photon end. Elwer-Born approximation is only valid at intermediate energies.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1982},
month = {1}
}

Thesis/Dissertation:
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