Production and test of isotopically modified Ge detectors for GERDA

The viability of producing BEGe-type detectors from isotopically modified germanium for the GERDA experiment is demonstrated by a complete test of the supply chain. GERDA is built to search for neutrinoless double beta (0vββ) decay of Ge using high-purity germanium detectors made of material enriched in ⁷⁶Ge. To reach a sensitivity for 0vββ decay of <;1.4·10²⁶ years, new active background suppression techniques are necessary. BEGe detectors enable a capability to efficiently identify and reject background events, while keeping large acceptance of 0vββ decay signal, by using novel pulse shape discrimination (PSD) techniques. The PSD as well as spectroscopic performance of prototype BEGe detectors from isotopically modified Ge was verified by comprehensive testing.