Neutron, proton and gamma-ray event identification with a HPGe detector through pulse shape analysis

The authors report on a series of preliminary experiments performed to investigate the current pulse shapes produced by gamma-ray, neutron, and proton interactions in a high-purity germanium (HPGe) detector. The pulse shapes are characterized on the basis of their time-to-peak (leading) and time-from-peak (trailing) edges. Each particle type generates a distinct range of current pulse shapes; this information can be used on a pulse-by-pulse basis to indicate which particle interacted in the detector. There is also an indication that current pulse shape information can be used to reduce the Compton background, which generally contributes to the background of any gamma-ray spectrum, by placing timing cuts on the leading and trailing edges of the current pulses