The Monte Carlo approach MCPUT for correcting pile-up distorted pulse-height spectra

Pulse pile-up distortion is a common problem for radiation spectroscopy measurements involving high counting rates. The Monte Carlo pile-up to true approach (MCPUT) is proposed and benchmarked in this article for correcting pile-up distorted pulse-height spectra to true spectra. In previous work, a Monte Carlo approach was used for predicting the pile-up distorted pulse-height spectra for high counting-rate measurements ("the forward calculation"). The present work improves the previous simulation by employing a better ADC dead-time model. Based on this improved "forward calculation", the MCPUT approach introduces an iterative procedure for correcting pile-up distortions. Experiments with an Fe-55 source and a Si(Li) detector are used for benchmarking purposes. The MCPUT corrected spectrum for the high counting-rate measurement shows excellent agreement with the measured true spectrum at low counting rate with reduced chi-square as the quantitative measure. The approach is also efficient, as accurate calculations are possible in a few minutes.