Isotopic and neutron yields of products from the asymmetric and near-symmetric proton-induced fission ofU233andU235

Abstract

The isotopic yields of Rb, In, and Cs from the 40-100 MeV proton-induced fission of $^{233}\mathrm{U}$ and $^{235}\mathrm{U}$, and the isotopic yields of Ga from the 80 and 100 MeV proton-induced fission of $^{233}\mathrm{U}$ have been measured by on-line mass spectrometry. The yields have been normalized to the independent formation cross sections of selected isotopes measured radiochemically. Total numbers of neutrons emitted per fission event have been deduced from the centroids of the isotopic distributions. The equal charge displacement, minimum potential energy, and unchanged charge distribution mechanisms have been investigated. It is found that the charge-division mechanism is fragment-mass dependent, the minimum potential energy postulate being attributed to asymmetric fission events and the unchanged charge distribution postulate being attributed to near-symmetric fission events.NUCLEAR REACTIONS, FISSION $^{233,235}\mathrm{U}(\mathrm{p},f)$, ${E}_{\mathrm{p}}=40 \mathrm{to} 100$ MeV: measured independent yields of Ga, Rb, In, Cs. Deduced total numbers of neutrons emitted in asymmetric (Rb, Cs) and near-symmetric (In) fission: charge-division mechanism.