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Are Einstein's transition probabilities for spontaneous emission constant in plasmas?An investigation is conducted with a ruby laser to experimentally confirm the quenching of spontaneous emission coefficients and propose a mechanism for the phenomenon. Results of previous experiments are examined to determine the consistency and validity of interpretations of the spontaneous emissions. For the C IV 3s-3p and 2s-3p transitions, the line-intensity ratios are found to be dependent on the separation of the laser from the target. Density gradients and Stark broadening are proposed to interpret the results in a way that does not invalidate the Einstein A values. The interpretation is extended to C III and N V, both of which demonstrate similar changes in A values in previous experiments. The apparent quenching of Ar II by photon collisions is explained by Rabi oscillations and power broadening in the argon-ion laser cavity. It is concluded that the changes in A values cannot result from dense plasma effects.
Document ID
19910061967
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Griem, H. R. (Maryland Univ. College Park, MD, United States)
Huang, Y. W. (Maryland Univ. College Park, MD, United States)
Wang, J.-S. (Maryland Univ. College Park, MD, United States)
Moreno, J. C. (Maryland, University College Park, United States)
Date Acquired
August 14, 2013
Publication Date
August 1, 1991
Publication Information
Publication: Physics of Fluids B
Volume: 3
Issue: 8 pt
ISSN: 0899-8221
Subject Category
PLASMA PHYSICS
Funding Number(s)
CONTRACT_GRANT: NSF PHY-82-17853
Distribution Limits
Public
Copyright
Other