Review of ( n,3 n) reaction cross-sections for fast neutrons and its dependence on the neutron excess term

Abstract

The available information on the ( n,3 n) reaction, as well as the neutron cross-sections for the neutron energies from 23 to 29 MeV are reviewed for the interval of 27 ⩽ Z ⩽ 83. For practical purposes, an empirical expression has been found by using the experimental ( n,3 n) cross-section values as a function of ( N- Z) and (E u + Q n) 1 2 where ( N- Z) is the neutron excess of the target nucleus, E u and Q n are the incident neutron energy and the ( n,3 n) reaction energy, respectively. It is seen that the empirical relation gives good fits with the experimental values.