Neutron‐Induced Reactions and Spectroscopy with GEANIE

A large number of partial γ‐ray cross sections produced in neutron‐induced reactions with neutrons in the energy range 1 < E_n (MeV) < 200 have been measured over the past eight years. Partial γ‐ray cross sections are measured as a function of incident neutron energy using the time‐of‐flight technique. Reaction channel cross sections were deduced from these measurements with the aid of nuclear modeling. Enabling facilities are the intense “white” source of neutrons at the LANSCE/WNR 60R 20‐meter flight path, and the precision γ‐ray spectrometry of the Compton‐suppressed Ge detector array GEANIE. The first focus of the measurements was on the ²³⁹Pu(n,2n) cross section, followed by a series of other experiments on nuclei throughout the periodic table, with an emphasis on neutron‐fluence activation detectors (or “RadChem detectors”). Representative measurements will be presented, along with the techniques. Experiments in progress and future plans are mentioned.