Independent yields of Kr and Xe fragments in the photofission of 237Np and 243Am odd nuclei

Abstract

Results are presented that were obtained by measuring the independent yields of Kr (A = 89–93) and Xe (A = 135–142) appearing as fragments in the photofission of 237Np and 243Am odd nuclei. The respective experiments were performed in a beam of bremsstrahlung photons from electrons accelerated to an energy of 25 MeV at the microtron of the Laboratory of Nuclear Reactions at the Joint Institute for Nuclear Research (JINR, Dubna). Use was made of the procedure involving the transportation of fragments emitted from the target by a gas flow along a capillary and the condensation of inert gases in a cryostat at liquid-nitrogen temperature. The identification of Kr and Xe appearing as fragments was performed by the gamma spectra of their daughter products. The mass-number distributions of the independent yields of Kr and Xe isotopes were obtained, along with those for the complementary fragments (Y and La in the fission of 237Np and Nb and Pr in the fission of 243Am).