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Title: Resonance enhancement of electron collision rates for fluorinelike ions

The distorted-wave approximation and similar weak-coupling methods are frequently used to calculate electron collision cross sections for studies of astrophysical and laboratory plasmas. Autoionizing resonances neglected in these approximations can significantly enhance the calculated rates for collisional excitation of some transitions in highly charged ions. We investigated the effects of such resonances on the excitation rates for n = 2 to n = 2 transitions in fluorinelike Fe, Se, Mo, Ag, Xe, and Eu. The background excitation rates were calculated using a relativistic distorted-wave approximation, and the detailed Auger and radiative rates were calculated using a multiconfiguration Dirac-Fock model. The largest effect is on the electric-dipole-forbidden transitions. The enhancement diminishes with increasing atomic number for all transitions.
Authors:
; ;
Publication Date:
OSTI Identifier:
6015824
DOE Contract Number:
W-7405-ENG-48
Resource Type:
Journal Article
Resource Relation:
Journal Name: Phys. Rev. A; (United States); Journal Volume: 36:7
Research Org:
High Temperature Physics Division, University of California, Lawrence Livermore National Laboratory, Livermore, California 94550
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; EUROPIUM IONS; ELECTRON-ION COLLISIONS; IRON IONS; MOLYBDENUM IONS; SELENIUM IONS; SILVER; XENON IONS; AUGER EFFECT; AUTOIONIZATION; CROSS SECTIONS; DISTORTED WAVE THEORY; E1-TRANSITIONS; EXCITATION; MULTICHARGED IONS; RADIATIVE DECAY; RESONANCE; CHARGED PARTICLES; COLLISIONS; ELECTRON COLLISIONS; ELEMENTS; ENERGY-LEVEL TRANSITIONS; ION COLLISIONS; IONIZATION; IONS; METALS; MULTIPOLE TRANSITIONS; TRANSITION ELEMENTS 640304* -- Atomic, Molecular & Chemical Physics-- Collision Phenomena