Neutron inelastic scattering as a background in the Majorana neutrinoless double-beta decay experiment

Neutrinoless double-beta decay searches play a major role in determining the effective Majorana neutrino mass and the Majorana nature of neutrinos. The MAJORANA experiment proposes to assemble an array of HPGe detectors to search for neutrinoless double-beta decay in 76Ge. Ultra-pure electro-formed Cu will form the cryostat and inner shielding material while Pb will comprise the remaining external shield. Neutron-induced γ-rays are a contribution to background for this and other double beta decay experiments. In some cases the excitation functions for highly excited state transitions of interest are not in the nuclear database. Measuring and understanding the high-energy neutron excitations of the shielding and detector materials for neutrinoless double beta decay experiments are crucial for interpreting results and establishing shielding requirements. Specific partial γ-ray cross sections were measured using the GEANIE spectrometer surrounding natural Pb, Cu and enriched Ge (76Ge) targets in a broad-spectrum neutron beam at LANSCE. The cross sections provide useful data for benchmarking Monte Carlo simulation of background events.