ISSN:
1434-601X
Keywords:
23.60.+e
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract Theα-branching ratios (b α ) of192,190,188Pb are measured using mass-separated sources. Different experimental set-ups are used — one detector as well as two detector set-ups — thereby detecting theα particles from the parent and/or viaα decay formed daughter nuclei, theβ-delayed gamma radiation from the parent and/or viaβ decay formed daughter nuclei and the Tl KX rays from electron capture decay. Values forb α of 6.2(6) 10−5 and 4.0(4) 10-3 were found for192,190Pb respectively. For188Pb, limits on theb α values were obtained: 0.03〈b α 〈0.10. A careful analysis of the previously reportedb α values showed that the discrepancies in theb α values were not due to inadequate correction procedures, as was suggested, but to experimental uncertainties in the efficiency determination of the different detection set-ups and to an unreliableβ-decay scheme for188Pb. Theb α obtained in this work show that the leadα decay is not faster than the Hgα decay and that there is no need to assume a disappearance of theZ=82 shell closure halfway betweenN=82 andN=126.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01291510
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