Blind source separation of HPGe output signals: a new pulse pile-up correction method

Abstract

The pulse pile-up phenomenon is one of the major problems of the gamma-ray spectrometry, especially at high counting rates. This phenomenon is considered herein, in signal processing point of view, as a blind source separation problem. Indeed, we present in this paper the application of the symetric prewhitening algorithm for the separation of overlapping pulses. The obtained results show that we can achieve the separation task using only three preamplifier's recordings. In case of pulse pile-up, the algorithm allows to separate the stacked pulses into two independent components. A third component is also extracted. This last was found to be strongly correlated to the detector's background noise. Otherwise, the algorithm permits to identify two independent components.