Measurements of 242Pu spontaneous fission neutron and gamma-ray energies and multiplicity distributions using the Los Alamos Chi-Nu detector array.

Measurements of neutrons from spontaneous fission (sf) are an important tool to Non-Destructive Assay (NDA) actinide quantities, and in particular for even-even Pu isotopes since these isotopes possess measurable spontaneous fission decay branches. In this work we studied both neutron and gamma ray emission from 242Pu. Data were acquired using the Chi-Nu array at the Los Alamos Neutron Science CEnter (LANSCE) Weapons Neutron Research (WNR) facility at Los Alamos National Laboratory (LANL). This work examines the Prompt Fission Neutron Spectrum (PFNS) using measured neutron time of flight and unfolding based on MCNP simulation, and Gamma Spectrum (PFGS) using measured liquid scintillator detector response and unfolding based on MCNP simulation. This work also examines the neutron and gamma ray multiplicity distributions, P(n) and P(gamma), and correlated neutron/gamma multiplicities.