THEORY OF (A,XN) REACTIONS

A new method for the study of (a,xn) reactions is presented (a=n,p,α,γ,HI). The method is applicable to reactions in which first a compound nucleus is created and later x neutrons are evaporated. The method allows the calculation of excitation functions for the emission of a specified number of neutrons, average neutron energies, and neutron spectra. The equations governing a succession of neutron emissions are derived from first principles. The effect of γ decay is incorporated. The effect of spin on decay rates is treated rigorously. The theory is used to calculate the excitation function for the reactions Ag109(α,n)In112m, Ag109(α,n)In112g, and Ag109(α,2n)In111. The comparison between measured and calculated values is discussed. © 1969 The American Physical Society.