Pulse Shape Analysis to Reduce the Background of BEGe Detectors

A simple technique for pulse shape discrimination in HPGe-detectors of the so-called BEGe type, based on just one parameter obtained from one signal read out, is presented here. This technique allows discriminating between pulses generated when the deposited energy is located within a small region of about 1 mm3 from the pulses generated when the energy is deposited at different locations several mm or cm apart. Two possible applications using this technique are: (i) experiments that look for neutrinoless double beta decay in 76Ge, such as GERDA; (ii) gamma spectrometry measurements where the Compton continuum can be reduced and the efficiency for cascading gamma-rays can remain high. With this active background reduction technique a Compton suppression factor of about 3 was obtained. The detector response may be influenced by the detector size. The detector used for this study had a diameter of 6 cm, a thickness of 2.6 cm and a relative efficiency of 19%. The results obtained with this detector were consistent with the results obtained by Budjas et al. [J Instrum 4:10, 2009] with a 50% relative efficiency BEGe detector.JRC.D.4-Nuclear physic