Pulse pile-up identification and reconstruction for liquid scintillator based neutron detectors

X. L. Luo*, V. Modamio, J. Nyberg, J. J. Valiente-Dobón, Q. Nishada, G. de Angelis, J. Agramunt, F.J. Egea, M. N. Erduran, S. Ertürk, G de France, A. Gadea, Vicente González, A. Goasduff, T. Hüyük, G. Jaworski, M. Moszyński, A. Di Nitto, M. Palacz, P.-A. SöderströmE. Sanchis, A. Triossi, R. Wadsworth

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


The issue of pulse pile-up is frequently encountered in nuclear experiments involving high counting rates, which will distort the pulse shapes and the energy spectra. A digital method of off-line processing of pile-up pulses is presented. The pile-up pulses were firstly identified by detecting the downward-going zero-crossings in the first-order derivative of the original signal, and then the constituent pulses were reconstructed based on comparing the pile-up pulse with four models that are generated by combining pairs of neutron and γ standard pulses together with a controllable time interval. The accuracy of this method in resolving the pile-up events was investigated as a function of the time interval between two pulses constituting a pile-up event. The obtained results show that the method is capable of disentangling two pulses with a time interval among them down to 20 ns, as well as classifying them as neutrons or γ rays. Furthermore, the error of reconstructing pile-up pulses could be kept below 6% when successive peaks were separated by more than 50 ns. By applying the method in a high counting rate of pile-up events measurement of the NEutron Detector Array (NEDA), it was empirically found that this method can reconstruct the pile-up pulses and perform neutron-γ discrimination quite accurately. It can also significantly correct the distorted pulse height spectrum due to pile-up events.

Original languageEnglish
Pages (from-to)59-65
Number of pages7
JournalNuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Early online date24 Apr 2018
Publication statusPublished - 21 Jul 2018

Bibliographical note

© 2018 Elsevier B.V. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy.


  • Digital
  • First-order derivative
  • Liquid scintillator
  • Neutron-γ discrimination
  • Pile-up

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