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Electron Excitation Cross Sections for the S II Transitions: 3s(exp 2)3p(exp 3) 4S(exp o) approaches 3s(exp 2)3p(exp 3) 2D(exp o), 2P(exp o), and 3s3p(exp 4) 4PExperimental and theoretical collisional excitation cross sections are reported for the transitions 3s(exp 2)3p(exp 3)4S(exp o) approaches 3s(exp 2)3p(exp 3) 2D(exp o), 2P(exp o), and 3s3P(exp 4) 4P in S II. The transition wavelengths (energies) are 6716 A (1.85 eV), 4069 A (3.05 eV), and 1256 A (9.87 eV), respectively. In the experiments, use is made of the energy-loss merged-beams method. The metastable fraction of the S II beam was assessed and minimized. The contribution of elastically scattered electrons was reduced by the use of a lowered solenoidal magnetic field and a modulated radio-frequency voltage on the analyzing plates and by retarding grids to reject the elastically scattered electrons with larger Larmor radii. For each transition, comparisons are made among experiments, the new 19 state R-matrix calculation, and three other close-coupling calculations.
Document ID
19990018165
Document Type
Reprint (Version printed in journal)
Authors
Liao, C. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA United States)
Chutjian, A. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA United States)
Hitz, D. (Centre National de la Recherche Scientifique Grenoble, France)
Tayal, S. S. (Atlanta Univ. GA United States)
Date Acquired
August 19, 2013
Publication Date
August 1, 1997
Publication Information
Publication: Astrophysical Journal
Volume: 484
Subject Category
Atomic and Molecular Physics
Distribution Limits
Public
Copyright
Other