Next-generation germanium spectrometer background reduction techniques at 2 MeV

The Majorana project, a next-generation 76Ge neutrinoless double-beta decay experiment being undertaken by a large international collaboration, has the goal of measuring the neutrinoless double-beta decay rate by observing monochromatic events at 2039 keV in 500 kg of isotopically enriched 76Ge gamma-ray spectrometers. In order to achieve the desired sensitivity limit, the background in the 2037-2041 keV region must be reduced to <1 event per year in the entire germanium array. The effects of various background reduction techniques, and the combination thereof, to produce a huge 76Ge spectrometer array with virtually zero background are discussed. (author)