Nuclear Closed Shells and Fission Yield Fine‐Structure

Abstract

AbstractNeutron binding energies have been computed in the region of closed shells and it is shown that besides the already known effects of closed shells these will also result in an abnormal dependence of the neutron binding energy of shell (S) plus 1, 3, 5, and 7 neutrons on the number of protons in the nucleus. These results have been used to predict the emission of both prompt and delayed neutrons from fission fragments. It has been shown that nuclides with neutron numbers S + 1, 3, 5, and 7 will emit the last neutron promptly and thus result in fine structure in the yield mass curve. The fission yields predicted on this basis are in good agreement with the observed ones along different decay chains and for different mass numbers, except at chain 135. To explain this it seems required that 82 neutron species are favored in the primary fission process.