The fast neutron induced fission of $^{240}$Pu and $^{242}$Pu

Abstract

We report the measurement of the TKE release in the fast neutron induced fission of $^{240}$Pu and $^{242}$Pu. The results are compared to the predictions of the GEF model, the CGMF model, and the model of Denisov and Sedykh as well as previous experimental work on these reactions. Our absolute measurements of the TKE release are in good agreement with the previous measurements of Nethaway \textit{et al.} for the interaction of 14.8 MeV neutrons with $^{240}$Pu \cite{Nethaway} and of Winkelmann and Aumann for the interaction of 15 MeV neutrons with $^{242}$Pu \cite{Winkelmann}. The general trends of the measured TKE values agree with phenomenological models but the variances of the TKE distributions are significantly less than predicted by various models. The mean post neutron emission TKE release decreases non- linearly with increasing neutron energy and can be represented as TKE(MeV) = 175.8 $\pm$ 0.3 - (2. 4 $\pm$ 0.8)log$_{10}$E$_n$ - (1.4 $\pm$0.4)log$_{10}$E$_{n}^2$ for $^{240}$Pu and TKE(MeV) = 177.1 $\pm$ 0.3 - (1.2 $\pm$ 0.9)log$_{10}$E$_n$ - (1.8 $\pm$0.5)log$_{10}$E$_{n}^2$ for $^{242}$Pu.