FLUORESCENCE YIELDS OF THE LII AND LIII SHELLS IN HEAVY ELEMENTS

Journal Article · Mon Jan 20 00:00:00 EST 1964 · Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D

DOI:https://doi.org/10.1103/PhysRev.133.A381· OSTI ID:4119021

Jopson, R. C.; Khan, J. M.; Mark, H.; Swift, C. D.; Williamson, M. A.

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)

• Research Organization: Univ. of California, Livermore, CA (United States)
• NSA Number: NSA-18-005928
• OSTI ID: 4119021
• Report Number(s): UCRL-7235; 0031-899X
• Journal Information: Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D, Vol. Vol: 133; Other Information: UCRL-7235. Orig. Receipt Date: 31-DEC-64
• Country of Publication: United States
• Language: English

Related Subjects

PHYSICS
ATOMIC MODELS
ATOMS
COINCIDENCE METHODS
ENERGY LEVELS
FLUORESCENCE
MASS
MEASURED VALUES
SCINTILLATION COUNTERS
X RADIATION