Influence of pileup rejection on nuclear counting, viewed from the time-domain perspective
Time-interval density distributions of accepted events in a HPGe gamma-ray detection set-up are measured with a time-interval digitizer. In particular, the effect of pulse-pileup rejection is investigated. Experimental data is obtained with two types of shaping amplifiers: a classical amplifier with semi-Gaussian pulse shaping and a gated-integrator amplifier. A theoretical model is developed to predict typical time-interval density distributions for stationary Poisson processes passing through a detector with count loss by pulse-pileup rejection. Good agreement is obtained between theoretical, measured and simulated time-interval spectra. It is found that, when counting is affected by pileup rejection, the true incoming count rate cannot simply be determined by fitting an exponential to the time-interval distributions. From the Laplace transform of the interval-density distribution, expressions are derived from the expectation value and the variance of the counts.
Bibliographic Reference: Article: Nuclear Instruments and Methods in Physics Research, 426 (1999), 564-582
Record Number: 199911128 / Last updated on: 1999-08-13
Original language: en
Available languages: en