학술논문
$\beta$ and $\beta$-delayed neutron decay of the $N=82$ nucleus $^{131}_{~49}$In$_{82}$
Document Type
Working Paper
Author
Dunlop, R.; Svensson, C. E.; Andreoiu, C.; Ball, G. C.; Bernier, N.; Bidaman, H.; Bildstein, V.; Bowry, M.; Cross, D. S.; Dillmann, I.; Dunlop, M. R.; Garcia, F. H.; Garnsworthy, A. B.; Garrett, P. E.; Hackman, G.; Henderson, J.; Measures, J.; Mücher, D.; Olaizola, B.; Ortner, K.; Park, J.; Petrache, C. M.; Pore, J. L.; Smith, J. K.; Southall, D.; Ticu, M.; Turko, J.; Whitmore, K.; Zidar, T.
Source
Subject
Language
Abstract
The half-lives of three $\beta$ decaying states of $^{131}_{~49}$In$_{82}$ have been measured with the GRIFFIN $\gamma$-ray spectrometer at the TRIUMF-ISAC facility to be $T_{1/2}(1/2^-)=328(15)$~ms, $T_{1/2}(9/2^+)=265(8)$~ms, and $T_{1/2}(21/2^+)=323(55)$~ms, respectively. The first observation of $\gamma$-rays following the $\beta n$ decay of $^{131}$In into $^{130}$Sn is reported. The $\beta$-delayed neutron emission probability is determined to be $P_{1n} = 12(7)\%$ for the $21/2^+$ state and $2.3(3)\%$ from the combined $1/2^-$ and $9/2^+$ states of $^{131}_{~49}$In$_{82}$ observed in this experiment. A significant expansion of the decay scheme of $^{131}$In, including 17 new excited states and 34 new $\gamma$-ray transitions in $^{131}_{~50}$Sn$_{81}$ is also reported. This leads to large changes in the deduced $\beta$ branching ratios to some of the low-lying states of $^{131}$Sn compared to previous work with implications for the strength of the first-forbidden $\beta$ transitions in the vicinity of doubly-magic $^{132}_{~50}$Sn$_{82}$.
Comment: 14 pages, 15 figures, 5 tables
Comment: 14 pages, 15 figures, 5 tables