Correlation studies of fission fragment neutron multiplicities

Abstract

We calculate neutron multiplicities from fission fragments with specified mass numbers for events having a specified total fragment kinetic energy. The shape evolution from the initial compound nucleus to the scission configurations is obtained with the Metropolis walk method on the five-dimensional potential-energy landscape, calculated with the macroscopic-microscopic method for the three-quadratic-surface shape family. Shape-dependent microscopic level densities are used to guide the random walk, to partition the intrinsic excitation energy between the two proto-fragments at scission, and to determine the spectrum of the neutrons evaporated from the fragments. The contributions to the total excitation energy of the resulting fragments from statistical excitation and shape distortion at scission is studied. Good agreement is obtained with available experimental data on neutron multiplicities in correlation with fission fragments from ${}^{235}$U(n${}_{\mathrm{th}}$,f). At higher neutron energies a superlong fission mode appears which affects the dependence of the observables on the total fragment kinetic energy.

arXiv comment12 pages, 10 figures

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Cited by in corpus (7)

• Theory of Nuclear Fission
• Generation of fragment angular momentum in fission
• Study of angular momentum effects in fission
• Fourier-over-Spheroid shape parametrization applied to nuclear fission dynamics
• ${}^{178}$Hg and asymmetric fission of neutron-deficient pre-actinides
• New developments in fission studies within the time-dependent density functional theory framework
• The fast neutron induced fission of ${}^{240}$Pu and ${}^{242}$Pu