A Method and Setup for Studying the Energy Dependence of Delayed Neutron Characteristics in Nuclear Fission Induced by Neutrons from the T(p, n), D(d, n), and T(d, n) Reactions

摘要

A method and a setup based on this method are described, with which it has for the first time become possible to measure the energy dependence of the absolute total and relative yields of delayed neutrons and the half-lives of their precursors from neutron-induced fission of heavy nuclei in the course of one experiment. T(p, n)3{sup left}He, D(d, n)3{sup left}He, and T(d, n)4{sup left}He nuclear reactions induced by high-energy charged-particle beams from the KT-2.5 electrostatic accelerator at the Institute of Physics and Power Engineering are used as sources of monoenergetic neutrons. The measured total delayed neutron yields from neutron-induced fission of 233{sup left}U and 239{sup left}Pu nuclei in the energy range of 0.37-4.7 MeV, as well as the relative yields of delayed neutrons and the half-lives of their precursors from neutron-induced fission of 239{sup left}Pu in the range of 15.8-17.9 MeV, are presented as an illustration of the method. The uncertainties of the data obtained by means of this method are shown to be significantly lower than the uncertainties of similar data measured using other techniques.