High temperature high density atomic environment and the Bremsstrahlung process

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1982

OSTI ID:5004591

Feng, I J

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.

• Research Organization: Pittsburgh Univ., PA (USA)
• OSTI ID: 5004591
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ALKALI METALS
ANGULAR DISTRIBUTION
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
ATOM COLLISIONS
ATOMS
BREMSSTRAHLUNG
CESIUM
CHARGED PARTICLES
COLLISIONS
COMPARATIVE EVALUATIONS
DENSITY
DISTRIBUTION
ELECTROMAGNETIC RADIATION
ELECTRON COLLISIONS
ELECTRON SPECTRA
ELECTRON-ATOM COLLISIONS
ELECTRON-ION COLLISIONS
ELEMENTARY PARTICLES
ELEMENTS
ENERGY LEVELS
FERMIONS
HIGH TEMPERATURE
ION COLLISIONS
IONIZATION
IONS
LEPTONS
METALS
PHYSICAL PROPERTIES
PLASMA
POLARIZATION
POSITRONS
RADIATIONS
SPECTRA
SPECTRAL SHIFT