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Physics, Instrumentation and Detectors, physics.ins-det,Nuclear Experiment, nucl-ex
Abstract:
An infrastructure to characterize germanium detectors has been designed and
constructed at the HADES Underground Research Laboratory, located in Mol
(Belgium). Thanks to the 223m overburden of clay and sand, the muon flux is
lowered by four orders of magnitude. This natural shield minimizes the exposure
of radio-pure germanium material to cosmic radiation resulting in a significant
suppression of cosmogenic activation in the germanium detectors. The project
has been strongly motivated by a special production of germanium detectors for
the GERDA experiment. GERDA, currently collecting data at the Laboratori
Nazionali del Gran Sasso of INFN, is searching for the neutrinoless double beta
decay of 76Ge. In the near future, GERDA will increase its mass and sensitivity
by adding new Broad Energy Germanium (BEGe) detectors. The production of the
BEGe detectors is done at Canberra in Olen (Belgium), located about 30km from
the underground test site. Therefore, HADES is used both for storage of the
crystals over night, during diode production, and for the characterization
measurements. A full quality control chain has been setup and tested on the
first seven prototype detectors delivered by the manufacturer at the beginning
of 2012. The screening capabilities demonstrate that the installed setup
fulfills a fast and complete set of measurements on the diodes and it can be
seen as a general test facility for the fast screening of high purity germanium
detectors. The results are of major importance for a future massive production
and characterization chain of germanium diodes foreseen for a possible next
generation 1-tonne double beta decay experiment with 76Ge.
