A comparison study of the pile-up correction algorithms

The pulse pile-up is a long-standing problem which deteriorates the energy, timing and spatial resolution of the radiation detection systems. Several algorithms have been developed for recovering the true pulse information using the available digital processing platforms. In this study, four well-established pile-up correction methods are numerically compared: single event reconstruction, template matching, maximum likelihood estimation and high-yield pile-up event recovery. Different pile-up waveforms are simulated by using the extracted parameters from the experimental data of a NaI(Tl) scintillation detector. The experimental pulses are taken from the charge sensitive preamplifier output, and therefore the methods are compared on the timescale of the RC constant of the preamplifier. Under such circumstance, the methods are compared with respect to their sensitivity to noise, variation of pulse shape, sampling rate and probable errors in time pick-off. In addition, their performance is assessed by calculating the experimental energy spectra of 137Cs at different high-count-rates. The results of the present study provide the benefits and limitations of each method, which can be used to select the best pile-up correction strategy for each specific application.