Applications of Event-by-Event Fission Modeling with FREYA

¹ Physics Division, Lawrence Livermore National Laboratory, Livermore, CA 94551, USA
² Physics Department, University of California, Davis, CA 95616, USA
³ Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA

^a e-mail: vogt2@llnl.gov

Abstract

The recently developed code FREYA (Fission Reaction Event Yield Algorithm) generates large samples of complete fission events, consisting of two receding product nuclei as well as a number of neutrons and photons, all with complete kinematic information. Thus it is possible to calculate arbitrary correlation observables whose behavior may provide unique insight into the fission process. We first discuss the present status of FREYA, which has now been extended to include spontaneous fission. Concentrating on ²³⁹Pu(n_th,f), ²⁴⁰Pu(sf) and ²⁵²Cf(sf), we discuss the neutron multiplicity correlations, the dependence of the neutron energy spectrum on the neutron multiplicity, and the relationship between the fragment kinetic energy and the number of neutrons and their energies. We also suggest novel fission observables that could be measured with modern detectors.