Pulse shape analysis of HPGe detector signals with a flash ADC system to improve the coincidence time resolution

Summary form only given. For the new large germanium detector arrays (e.g. EUROGAM, Gammasphere, Euroball, etc.) which are currently under design/in construction, an improved time resolution is desirable to improve the coincidence time resolution. Currently with Ge-Ge timing one can reach a time resolution of the order of 20 ns with large detectors (>30% efficiency). By digitizing the signal every 10 ns with a flash analog-to-digital converter (ADC) system and a following analysis of the digitized pulse, the time resolution can improve relative to conventional techniques (time filter and constant fraction). Measurements show a time resolution of about 9 ns using a conventional technique for a fast plastic and a high-purity germanium (HPGe) detector. With digital pulse shape analysis a resolution of 3 ns is observed.<>