Independent yields of 92mNb in the thermal neutron-induced fission of 233U, 235U and 239Pu

Abstract

Independent yields of 92 m Nb were measured in the thermal neutron-induced fission of 233U, 235U, and 239Pu, using radiochemical techniques. Upper limits of < 2.2 × 10 −8% and < 4.6 × 10 −8% were found for 233U and 235U, respectively. The independent yield for 239Pu was determined to be (11 ± 6) × 10 −8%. This yield is much higher than values predicted from models of charge and isotopic distributions. It probably reflects the influence of the nearby closed 50 neutron shell.