Surrogate ratio method in the actinide region using the (α,α'f) reaction

Abstract

In the Surrogate Method, the measured decay probability of a compound nucleus formed via a direct reaction is used to extract the cross section for a reaction with a different entrance channel that proceeds through the same compound nucleus. An extension of the Surrogate Method, the Surrogate Ratio Method (SRM), uses a ratio of measured decay probabilities to infer an unknown cross section relative to a known one. To test the SRM we compare the direct-reaction-induced fission probability ratio of $^{234}\mathrm{U}(\ensuremath{\alpha},{\ensuremath{\alpha}}^{'}f)$ to $^{236}\mathrm{U}(\ensuremath{\alpha},{\ensuremath{\alpha}}^{'}f)$ with the ratio of cross sections of $^{233}\mathrm{U}(n,f)$ to $^{235}\mathrm{U}(n,f)$. These ratios were found to be in agreement over an equivalent neutron energy range of 0.4--18 MeV.