A MULTI-PARAMETRIC WAVE-FORM ANALYSIS OF GE DETECTOR SIGNAL BASED ON FAST ADC DIGITIZING TECHNIQUE

A fast digitizing system was applied to a new waveform analysis of gamma-ray spectrometry, where coaxial Ge detector signals were analyzed by a fast ADC (200MHz/10bits) combined with a UNIX workstation. Multi-parametric analysis of each pulse waveform has been examined using two parameters. One parameter was a signal risetime (tr) and the other was a shape index (Ra) which describes the convexity or concavity of waveform in the pulse risetime region. A set of two parameters (tr and Ra) can indicate the gamma-ray reaction position for one collision event, which agreed well with experiments using a collimated Co-57 gamma-ray source. The selection of multiple scattered events gave a better peak-to-Compton ratio of 128:1, which was 3.4 times higher than the value without this selection.