| Irfu-11-13
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| Measurements of the $\beta$-decay half-lives and $\gamma$-ray emission probabilities of $^{244gs}Am$ and $^{244m}Am$ isotopes for the $^{243}Am$ capture cross sections
determination. |
| A. Letourneau, I. AlMahamid, E. Barat, Th. Dautremer, F. Marie, P. Mutti |
| Recently it was required by an IAEA Coordinated Research Project further studies on the decay of actinides
and in particular on the b-decay of 244Am. In this paper we report on an experiment to measure the b-decay
half-lives of the isomeric and the ground states of 244Am. These data were obtained thanks to the use of
ADONIS a high counting rate acquisition system. The obtained values amount to T1/2=28.3±1.3 minutes for
244mAm and T1/2=10.65±0.12 hours for 244gsAm that is slightly higher than the evaluated ones. Thanks to
the use of coupled a- and g-spectroscopic techniques we also measured the total thermal capture cross section
and the capture branching ratio to the isomeric state of 244Am which amount to tot = (81:3 2:5) and
BR = 0:953 0:02 respectively. Using these measured partial cross sections we have then calculated new
absolute g-emission probabilities for the decay of the ground and the isomeric states. No large discrepancies
were observed with previous evaluated data, but we largely reduce the uncertainties on the intensities. |
