Autoionizing resonances in electronimpact excitation of oxygenlike selenium
Abstract
We have investigated the contributions of doubly excited, autoionizing resonances to the rate coefficients for electronimpact excitation of the n = 2 to n = 2 transitions in oxygenlike selenium. The cross sections for direct excitation were calculated using a relativistic distortedwave approximation. The detailed Auger and radiative rates required for evaluating the resonance contributions were calculated using a multiconfigurational DiracFock model. The largest effect is on the electricdipoleforbidden transitions. For some J = 0 to J = 0 transitions involving twoelectron excitations, the resonances enhance the collisional excitation rates by factors up to 10/sup 4/ at electron temperatures relevant for laboratory plasmas.
 Authors:
 Publication Date:
 Research Org.:
 High Temperature Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550
 OSTI Identifier:
 7065546
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Phys. Rev. A; (United States); Journal Volume: 38:7
 Country of Publication:
 United States
 Language:
 English
 Subject:
 74 ATOMIC AND MOLECULAR PHYSICS; SELENIUM IONS; AUTOIONIZATION; CROSS SECTIONS; DISTORTED WAVE THEORY; ELECTRONION COLLISIONS; EXCITATION; RESONANCE; AUGMENTATION; ISOELECTRONIC ATOMS; KINETICS; OXYGEN; PLASMA; USES; ATOMS; CHARGED PARTICLES; COLLISIONS; ELECTRON COLLISIONS; ELEMENTS; ENERGYLEVEL TRANSITIONS; ION COLLISIONS; IONIZATION; IONS; NONMETALS; 640304*  Atomic, Molecular & Chemical Physics Collision Phenomena
Citation Formats
Reed, K.J., Chen, M.H., and Hazi, A.U. Autoionizing resonances in electronimpact excitation of oxygenlike selenium. United States: N. p., 1988.
Web. doi:10.1103/PhysRevA.38.3319.
Reed, K.J., Chen, M.H., & Hazi, A.U. Autoionizing resonances in electronimpact excitation of oxygenlike selenium. United States. doi:10.1103/PhysRevA.38.3319.
Reed, K.J., Chen, M.H., and Hazi, A.U. 1988.
"Autoionizing resonances in electronimpact excitation of oxygenlike selenium". United States.
doi:10.1103/PhysRevA.38.3319.
@article{osti_7065546,
title = {Autoionizing resonances in electronimpact excitation of oxygenlike selenium},
author = {Reed, K.J. and Chen, M.H. and Hazi, A.U.},
abstractNote = {We have investigated the contributions of doubly excited, autoionizing resonances to the rate coefficients for electronimpact excitation of the n = 2 to n = 2 transitions in oxygenlike selenium. The cross sections for direct excitation were calculated using a relativistic distortedwave approximation. The detailed Auger and radiative rates required for evaluating the resonance contributions were calculated using a multiconfigurational DiracFock model. The largest effect is on the electricdipoleforbidden transitions. For some J = 0 to J = 0 transitions involving twoelectron excitations, the resonances enhance the collisional excitation rates by factors up to 10/sup 4/ at electron temperatures relevant for laboratory plasmas.},
doi = {10.1103/PhysRevA.38.3319},
journal = {Phys. Rev. A; (United States)},
number = ,
volume = 38:7,
place = {United States},
year = 1988,
month =
}

Direct and resonance excitation rate coefficients have been calculated for transitions between states with principal quantum number {ital n}=3 in Nelike selenium. A relativistic distortedwave method was used to compute the direct excitation rate coefficients and the resonance excitation rate coefficients were obtained using a multiconfiguration DiracFock method. The effect of autoionizing resonances has been found to be significant for most transitions, especially at low temperatures. The resonances enhance the rate coefficients for some electricdipoleallowed transitions by as much as a factor of 2. For strongly forbidden transitions, resonances can increase the rate coefficients by more than an order ofmore »

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Contributions of autoionizing resonances to the n = 22 electron collisional excitation rates for Belike ions
The contributions of autoionizing resonances to the electronimpact excitationrate coefficients for the n = 2 to n = 2 transitions in Belike ions have been evaluated for six ions with atomic numbers Z = 30, 34, 36, 42, 47, and 54. The calculations were carried out in the isolatedresonance approximation. Interference between direct and resonance channels was neglected. The detailed Auger and radiative rates were computed using the multiconfiguration DiracFock model. Results for the 45 transitions among 10 states from 1s/sup 2/2l2l' configurations are listed. For electricdipoleallowed transitions, the contributions from the autoionizing resonances are quite small. However, the autoionizingmore »