The response of the Euroball Cluster detector to γ-radiation up to 10 MeV

The Euroball Cluster detector consists of seven closely packed hexagonal encapsulated germanium detectors which are mounted in a common cryostat and surrounded by a BGO suppression shield. By adding back the Compton scattered events between the seven germanium detectors the detector system behaves similar as a single germanium detector with a volume of 2000 cm ³. The response of this very large germanium detector to γ-rays up to 10 MeV has been measured using a short lived ²⁴Al source produced at the Cologne FN Tandem accelerator. At 10 MeV the efficiency of the Cluster detector is nearly one order of magnitude larger than that of a 30% germanium detector.