INDEPENDENT YIELDS OF 124Sb AND 126sb IN THERMAL NEUTRON INDUCED FISSION AND THEIR IMPLICATION ON THE EMPIRICAL Zp FUNCTION

Abstract

The independent fission yields in thermal neutron induced fission of ²³⁵U have been measured to be (9.5 ± 1.4)•10⁻⁶% and (1.04 ± 0.17)•10⁻³% for ^124gSb and ^126gSb, respectively. The total independent yields for all isomers of these nuclides are estimated to be (1.2 ± 0.2)•10⁻⁵% for ¹²⁴Sb and (3.7 ± 0.6)•10⁻³% for ¹²⁶Sb using a Huizenga–Vandenbosch approach for estimating population of isomeric states.These data do not seem to support a 50 proton shell effect on the Z_p function, using the "unique" charge distribution curve of Wahl. A revised Wahl plot based on recent information on neutron emission from individual fission fragments is given and discussed in view of shell effects in fission. It is shown that the effect of the Z_p function of the 50 proton shell is very small.