Accession Number : AD0615077

Title :   INFLUENCE OF FIELD INHOMOGENEITY ON IONIC LINE BROADENING,

Corporate Author : LOCKHEED MISSILES AND SPACE CO PALO ALTO CALIF

Personal Author(s) : Muller,Karl Gerhard

Report Date : 21 SEP 1964

Pagination or Media Count : 21

Abstract : The usual calculation of the ionic line broadening assumes a constant electric field, acting on an emitting atom. For a many-electron atom the quadratic Stark effect produces a shift proportional to 1/R to the fourth power where R is the distance perturber-atom. The actual Coulomb field of the ions possesses a field gradient, which for levels with a quadrupole moment causes a perturbation with 1/R-cubed. For N independently distributed ions, the probability distribution of the field gradient is calculated. Three approximate cases are discussed: the nearest neighbor approximation, the approximation of spatially fixed eigen-functions, and the nearest neighbour approximation of spatially fixed eigenfunctions. The line profile due to the quasistatic gradient of the field is calculated for these three assumptions. A critical density can be derived by comparing the effect of the field inhomogeneity with the quadratic Stark effect. Below this critical density the effect of the field inhomogeneity dominates. For the example of neutral helium lines the critical density is evaluated and goes up to 10 to the 16th power - 10 to the 17th power particles per cu cm. (Author)

Descriptors :   (*ATOMIC SPECTROSCOPY, PERTURBATION THEORY), (*FIELD THEORY, ATOMIC SPECTROSCOPY), (*LINE SPECTRA, IONS), (*PERTURBATION THEORY, ATOMIC SPECTROSCOPY), ELECTRIC FIELDS, PLASMA FIELDS, ATOMIC ENERGY LEVELS, ELECTRON TRANSITIONS, POTENTIAL THEORY, POWER SERIES, PROBABILITY, NUMERICAL METHODS AND PROCEDURES

Distribution Statement : APPROVED FOR PUBLIC RELEASE