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Low-energy electron-atom bremsstrahlungThis paper extends recent work providing an elementary calculation of bremsstrahlung and opacity associated with the scattering of low-energy electrons by neutral atoms and molecules. The method applies when the scattering potential is 'hard' or when the collision time is short, applying the classical soft-photon emission probability formula for arbitrary bremsstrahlung photon energy. However, now, in addition to correcting the probability factor for finite bremsstrahlung photon energy, another factor corrects for the reduced phase space available to the outgoing electron. The bremsstrahlung cross section and opacity are then computed directly from the elastic scattering cross section, determined experimentally or calculated; a small (approximately 10 percent) correction is computed from the anisotropic term in the elastic scattering cross section. The opacity is evaluated for electron scattering by H, He, and H2 using experimentally determined values for the elastic scattering cross section, and is compared with more elaborate calculations. The agreement is good (within 10 percent), indicating an accuracy for the general method comparable to variations among the results of different elaborate theoretical computations. The agreement seems to validate the basic approximation of short collision time even at large bremsstrahlung photon energy for electron energies and temperatures up to a few eV.
Document ID
19860045905
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Gould, R. J.
(California, University La Jolla, United States)
Date Acquired
August 12, 2013
Publication Date
March 1, 1986
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 302
ISSN: 0004-637X
Subject Category
Atomic And Molecular Physics
Accession Number
86A30643
Funding Number(s)
CONTRACT_GRANT: NGR-05-005-004
Distribution Limits
Public
Copyright
Other

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