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Author Jopson, R. C. ♦ Khan, J. M. ♦ Mark, H. ♦ Swift, C. D. ♦ Williamson, M. A.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword PHYSICS ♦ ATOMIC MODELS ♦ ATOMS ♦ COINCIDENCE METHODS ♦ ENERGY LEVELS ♦ FLUORESCENCE ♦ MASS ♦ MEASURED VALUES ♦ SCINTILLATION COUNTERS ♦ X RADIATION
Abstract A method was developed to measure the fluorescence yields of the L/sub III/ subshells in many heavy elements. This method is closely related to the K to L x-ray coincidence measurements used to determine omega /sub KL/ the partial L shell yield following K x-ray emission. The fluorescence yield omega /sub KL/ is a linear combination of omega /sub LII/ and omega /sub LIII/, the fluorescence yields of the L/sub II/ and L/sub III/ subshells. The scintillation counters used to perform the coincidence experiments cannot separate the two components (K/sub alpha 1/ and K/sub alpha 2/) of the K/sub a/ x rays, and thus the experiment determines only the average fluorescence yield omega /sub KL/. There are a number of elements possessing K absorption edges between the K/sub alpha 1/ and K/sub alpha 2/ x rays of the target materials. By using one of these elements as a secondary radiator, it is possible to eliminate all pulses in the K x-ray counter due to K/sub alpha 2/ x rays. The only target x rays contributing to the coincidence rate are the K/sub alpha 1/ x rays, which are caused by L/sub III/ yields K transitions. The observed coincidence rate is therefore proportional to omega /sub LIII/. Values of omega /sub LII/ can then be computed using previous measurements of omega /sub KL/. (auth)
ISSN 0031899X
Educational Use Research
Learning Resource Type Article
Publisher Date 1964-01-20
Publisher Department Univ. of California, Livermore
Publisher Place United States
Journal Physical Review
Volume Number 133
Technical Publication No. UCRL-7235
Organization Univ. of California, Livermore


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