Nuclear Science and Techniques

《核技术》(英文版) ISSN 1001-8042 CN 31-1559/TL     2019 Impact factor 1.556

Nuclear Science and Techniques ›› 2019, Vol. 30 ›› Issue (5): 84 doi: 10.1007/s41365-019-0595-1


Fast pulse sampling module for real-time neutron–gamma discrimination

Jia-Le Cai1,2 • Dao-Wu Li1 • Pei-Lin Wang1 • Zhi-Ming Zhang1 • Xiao-Hui Li1 • Bao-Tong Feng1 • Ting-Ting Hu1 • Teng Tong1 • Wei Zhou1 • Long Wei1,2   

  1. 1 Beijing Engineering Research Center of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
    2 School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2018-09-05 Revised:2018-12-18 Accepted:2018-12-22
  • Contact: Long Wei
  • Supported by:
    This work was supported by the Instrument Developing Project of the Chinese Academy of Sciences (No. 29201707).
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Jia-Le Cai, Dao-Wu Li, Pei-Lin Wang, Zhi-Ming Zhang, Xiao-Hui Li, Bao-Tong Feng, Ting-Ting Hu, Teng Tong, Wei Zhou, Long Wei. Fast pulse sampling module for real-time neutron–gamma discrimination.Nuclear Science and Techniques, 2019, 30(5): 84     doi: 10.1007/s41365-019-0595-1

Abstract: An adaptable and compact fast pulse sampling module was developed for the neutron–gamma discrimination. The developed module is well suited for low-cost and low-power consumption applications. It is based on the Domino Ring Sampler 4 (DRS4) chip, which offers fast sampling speeds up to 5.12 giga samples per second (GSPS) to digitize pulses from front-end detectors. The high-resolution GSPS data is useful for obtaining precise real-time neutron–gamma discrimination results directly in this module. In this study, we have implemented real-time data analysis in a field programmable gate array. Real-time data analysis involves two aspects: digital waveform integral and digital pulse shape discrimination (PSD). It can significantly reduce the system dead time and data rate processed offline. Plastic scintillators (EJ-299-33), which have proven capable of PSD, were adopted as neutron detectors in the experiments. A photomultiplier tube (PMT) (model #XP2020) was coupled to one end of a detector to collect the output light from it. The pulse output from the anode of the PMT was directly passed onto the fast sampling module. The fast pulse sampling module was operated at 1 GSPS and 2 GSPS in these experiments, and the AmBe-241 source was used to examine the neutron–gamma discrimination quality. The PSD results with different sampling rates and energy thresholds were evaluated. The figure of merit (FOM) was used to describe the neutron–gamma discrimination quality. The best FOM value of 0.91 was obtained at 2 GSPS and 1 GSPS sampling rates with an energy threshold of 1.5 MeVee (electron equivalent).

Key words: Real time, Neutron–gamma discrimination, Domino Ring Sampler 4, Plastic scintillators