Influence of relaxation phenomena in the unified description of resonant and nonresonant radiative transitions

Journal Article · Sat Oct 01 04:00:00 EDT 1994 · Physical Review A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.50.3005· OSTI ID:7032480

Jacobs, V L ^[1]; Cooper, J ^[2]; Haan, S L ^[3]

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1. Condensed Matter and Radiation Science Division, Code 6693, Naval Research Laboratory, Washington, D.C. 20375-5345 (United States)
2. Joint Institute for Laboratory Astrophysics and Department of Physics, University of Colorado, Boulder, Colorado 80309-0440 (United States)
3. Department of Physics, Calvin College, Grand Rapids, Michigan 49546 (United States)

A comprehensive quantum-mechanical description of resonant and nonresonant radiative transitions in complex electronic systems is developed, using a density-matrix approach. Applications are made to the unified treatment of radiative and dielectronic recombination of electrons with many-electron ions in high-temperature plasmas and to the unified treatment of transverse bound-bound and free-bound radiative transitions of energetic electrons channeled in crystal lattices. Both time-independent (resolvent-operator) and time-dependent (equation-of-motion) formulations of the density-matrix approach are presented. Liouville-space projection-operator techniques, developed in the nonequilibrium quantum-statistical-mechanics description of relaxation phenomena, are employed. Self-consistent treatments are achieved for the excited-level populations and the spectral-line shapes. Applications are discussed for the broadening of atomic spectral lines by autoionization processes, radiative transitions, charged-particle collisions, and the action of the plasma electric microfields, and also for electron-channeling-radiation broadening by electron-electron, electron-photon, and electron-phonon interactions in a crystal lattice. The unified treatment of resonant and nonresonant radiative transitions is accomplished by means of a partition of the relevant'' Liouville space into separate subspaces corresponding to discrete resonance and nonresonant continuum states of the electronic system of interest. Although only single-photon processes are considered and only lowest-order quantum-electrodynamical perturbation theory is explicitly evaluated for the electron interaction with the radiation field, the general resolvent-operator and propagator formulations that are presented in this investigation can be applied to the descrption of multiphoton processes and, with the suitable renormalization, to the incorporation of radiative corrections to the transition probabilities.

• DOE Contract Number: AI02-93ER54198
• OSTI ID: 7032480
• Journal Information: Physical Review A; (United States), Journal Name: Physical Review A; (United States) Vol. 50:4; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

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70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700320 -- Plasma Diagnostic Techniques & Instrumentation-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
74 ATOMIC AND MOLECULAR PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CHANNELING
COLLISIONS
CRYSTALS
DECAY
DENSITY MATRIX
DIFFERENTIAL EQUATIONS
ELECTRON CHANNELING
ELECTRON COLLISIONS
ELECTRON-ION COLLISIONS
EQUATIONS
EQUATIONS OF MOTION
HOT PLASMA
ION COLLISIONS
LINE BROADENING
MATRICES
MECHANICS
PARTIAL DIFFERENTIAL EQUATIONS
PARTICLE DECAY
PLASMA
QUANTUM MECHANICS
RADIATIVE DECAY
RECOMBINATION
RELAXATION
RESONANCE
TIME DEPENDENCE
USES