Optimized spin assignments of s-wave neutron resonances

The multiplicity of γ ‐ ray emission following neutron capture at isolated resonances carries valuable information on the resonance spin. Several methods utilizing this information have been developed. The latest method was recently introduced for analyzing the data from time-of-flight measurements with 4 π γ ‐ calorimetric detection systems. The present paper describes a generalization of this method. The goal is the separation of the γ ‐ emission yields belonging to the two neutron capturing state spins of isolated (or even unresolved) s-wave neutron resonances on targets with non-zero spin. The formalism for performing this separation is described and then tested on artificially generated data. This new method was applied to the γ ‐ multiplicity data obtained for the Sm 147 ( n , γ ) Sm 148 reaction using the DANCE detector system at the LANSCE facility at Los Alamos National Laboratory. The analyzing power of the upgraded method is supported by combined dicebox and geant4 simulations of the fluctuation properties of the γ ‐ multiplicity distributions.