Incorporating a two-step mechanism into calculations of (p,t) reactions used to populate compound nucleus spin-parity distributions in support of surrogate measurements

Abstract

The surrogate reaction method may be used to determine the cross section for neutron-induced reactions not accessible through standard experimental techniques by creating the same compound nucleus which the desired reaction would pass through, but via a different entrance channel. A variety of direct reactions have been employed in order to generate the required compound nuclei for surrogate studies. In this work, a previously developed (p,t) reaction model has been extended to incorporate a two-step reaction mechanism, which takes the form of sequential neutron transfer. This updated model is applied to the 92Zr(p,t)90Zr reaction and is found to modify the strengths of the previously predicted populated levels. It is planned that this improved (p,t) model will be used to attempt to constrain cross section predictions for a number of (n,γ) reactions in future, as well as provide a possible comparison against other surrogate studies utilising different direct reactions such as (p,d).