Accession Number : AD0266647

Title :   THE DECAY ENERGY OF BI-205

Corporate Author : NOBEL INST FOR PHYSICS STOCKHOLM (SWEDEN)

Personal Author(s) : BONACALZA,E.C.O. ; THIEBERGER,P. ; BERGSTROM,I.

Report Date : 25 SEP 1961

Pagination or Media Count : 1

Abstract : The decay energy of Bi-205 was determined by measuring the K and L X-rays which follow electron capture and feed the 2567 keV and 2610 keV levels. In this way the K to L, K to total and L to total capture ratios were found. Comparing these values with theoretical predictions, a total decay energy of 2703 ! 6 keV was established. This corresponds to a neutrino energy of 46 keV for K-capture to the 2567 keV level. Since this value disagreed with the previously determined maximum positron energy feeding the 703 keV level, the positron spectrum was remeasured and a value of 976 ! 10 keV was found. This yields a total decay energy of 2701 ! 10 keV, in good agreement with the capture value. K and L X-rays feeding the 1766 keV level were measured as a check of the method since, for such a large spacing, the ratios are rather insensitive to energy variations. The log ft values for the E.C. decay to the 2567 keV and 2610 keV levels were calculated yielding values of 6.60 ! 0.05 and 6.34 ! 0.06 respectively. (Author)

Descriptors :   *BETA DECAY, *BISMUTH, *ISOTOPES, ATOMIC SPECTROSCOPY, BREMSSTRAHLUNG, ELECTRON CAPTURE, ENERGY, EQUATIONS, EXPERIMENTAL DATA, GAMMA RAYS, NEUTRINOS, NUCLEAR REACTIONS, NUCLEAR SHELL MODELS, POSITRONS, RADIOACTIVE DECAY, THEORY, X RAYS

Distribution Statement : APPROVED FOR PUBLIC RELEASE