ββ Decay and Dark Matter Studies*

Neutrinoless double beta (0νββ) decay studies are both the best way to determine the Majorana nature of the neutrino and its effective mass. Many experiments searching for 0νββ decay, as well as other rare event physics such as dark matter interactions, use ⁷⁶Ge as the detection medium (and also as the source in 0νββ searches; Q value = 2039 keV). Consequently, due to the rarity of these events (T^0ν_½ > 10²⁴ years), these experiments require an ultra-low background environment in addition to highly precise background characterization. Some of the more problematic backgrounds are those from neutron interactions such as neutron capture (n,γ) and neutron inelastic scattering (n,n’γ) reactions. An experiment has been performed at the Triangle Universities Nuclear Laboratory (TUNL) to investigate the neutron inelastic scattering cross section on ⁷⁶Ge at E_n = 4.5 MeV. The data from this experiment is currently being analyzed, and the materials to be presented here include experimental setup, analysis procedures and techniques, and present status.