Identification of the New Neutron-Rich Isotopes 70-74 Ni and 74-77 Cu in Thermal Neutron Fission of 235 U

Abstract
The unknown isotopes 70-74Ni and 74-77Cu were identified in thermal neutron fission of 235U, using the recoil separator Lohengrin and ΔE - E detection techniques. Isotopic yields, for preselected values of ionic charge and kinetic energy of the fission fragments in the mass range A = 70 ÷ 80, were measured down to 10-9 fragments/fission (f/f). Mass yields for the masses 70 and 71 and elemental yields for nickel and copper are estimated.