Nucleation and cluster formation in low-density nucleonic matter: A mechanism for ternary fission

Abstract

Ternary fission yields in the reaction 241 Pu(n th , f) are calculated using a new model which assumes a nucleation-time moderated chemical equilibrium in the low density matter which constitutes the neck region of the scissioning system. The temperature, density, proton fraction and fission time required to fit the experimental data are derived and discussed. A reasonably good fit to the experimental data is obtained. This model provides a natural explanation for the observed yields of heavier isotopes relative to those of the lighter isotopes, the observation of low proton yields relative to 2 H and 3 H yields and the non-observation of 3 He, all features which are shared by similar thermal neutron induced and spontaneous fissioning systems.

Production of neutron-rich heavy nuclei around $$N = 162$$ in multinucleon transfer reactions

“…Recently, the MNT reaction mechanism was investigated both in experiments and in theories around the neutron shell closure of N = 126. The production cross sections, total kinetic energy spectra and angular distributions were measured in the reactions of 136 Xe + 208 Pb [24,25], 136 Xe + 198 Pt [26,27], 156,160 Gd + 186 W [28], and 238 U + 232 Th [29]. Recently, the new isotope 241 U was created in the MNT reactions of 238 U + 198 Pt [30].…”

Production of neutron-rich heavy nuclei around N = 162 in multinucleon transfer reactions

“…The reaction mechanism is concentrated on the neutron-rich nuclei around the shell closure N = 126. The MNT fragments were measured in the reactions of 136 Xe + 208 Pb [22,23], 136 Xe + 198 Pt [24], 156,160 Gd + 186 W [25], and 238 U + 232 Th [26]. The neutron-rich nuclides around N = 126 have important application in understanding the origin of heavy elements from iron to uranium in the r -process of astrophysics.…”