Charge Distribution in the Fission ofNp237andPu239with Intermediate-Energy Helium Ions

Abstract

The independent yields of ten fission products from the fission of ${\mathrm{Np}}^{237}$ induced by 40.5-MeV helium ions and from the fission of ${\mathrm{Pu}}^{239}$ induced by 32.0-MeV helium ions have been measured radio chemically. The data can be interpreted in terms of the equal-charge-displacement (E.C.D.) hypothesis, and less rigorously, by the constant-charge-ratio proposal. The most applicable mass equation for the determination of the E.C.D. parameters was found to be a continuous non-shell-corrected function. Information on neutron yield as a function of fission-product mass has been inferred from the charge division. There is no evidence from this research for a 50-proton shell effect on yields or for an isomeric state of ${\mathrm{Nb}}^{96}$.