Confirmation of High Neutron Yields for Ba-Mo from SF of $^{252}$Cf
ORAL
Abstract
A careful analysis of the yield matrix of coincident pairs of barium (Z = 56) and molybdenum (Z = 42) fission fragments has been made in the present study. The neutron multiplicity yields of Ba-Mo, Ce-Zr, Te-Pd and Nd-Sr have been studied with improved precision by using $\gamma$-$\gamma$-$\gamma$-$\gamma$ as well $\gamma$-$\gamma$-$\gamma$ coincidence data and the latest level scheme structures of these nuclei. The results clearly confirm that the Ba-Mo yield data have a second hot fission mode where 8, 9, and 10 neutron evaporation channels are observed. These higher neutron evaporation channels are not observed in other fission pairs. The second mode has an intensity of $\sim$1.3$\%$. This mode can indicate that $^{144}$Ba is likely hyperdeformed at scission to give rise to such high neutron multiplicities. A new experiment is being planned to do fission fragment-$\gamma$-$\gamma$ coincidence studies to investigate details of the fission process and to study new more neutron-rich nuclei.
*The work at Vanderbilt University and Lawrence Berkeley National Laboratory are supported by the US Department of Energy under Grant No. DE-FG05-88ER40407 and Contract No. DE-AC03-76SF00098. The work at Tsinghua University was supported by the National Natural Science Foundation of China under Grant No. 11175095.
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