Cumulative yields of stable and long-lived isotopes of ruthenium and palladium in neutron-induced fission

Abstract

The relative cumulative yields of nine stable and long-lived isotopes of ruthenium and palladium (masses 101 to 110) produced in the thermal neutron fission of 233U and in the thermal and epicadmium neutron fission of 235U and 239Pu have been measured using a solid source mass spectrometer and isotope dilution techniques. Absolute yields of these isotopes for the thermal neutron fission of 233U, 235U, and 239Pu are obtained using normalization procedures. These yields provide the first experimentally determined yields of the palladium masses 105, 106, 107, 108, and 110.In the thermal fission of 233U and 235U the ruthenium isotope yields obtained are in general agreement with previously determined values, although discrepancies exist of the order of 10% at masses 103, 104, and 106 for thermal fission of 235U.A plot of the ruthenium and palladium isotope mass yields together with the previously determined yields for the cadmium and tin isotopes indicate a significant depression in the mass yield curve at masses 111 and 114 for 233U and 235U thermal fission, respectively. In the 235U epicadmium fission, yields at even mass numbers are relatively higher than those at odd numbers, resulting in a zigzag yield curve in the 101 to 110 mass region.