Characterization of a CLYC Detector and Validation of the Monte Carlo Simulation by Measurement Experiments

Abstract

Background: Simultaneous detection of neutrons and gamma rays have become much more practicable, by taking advantage of good gamma-ray discrimination properties using pulse shape discrimination (PSD) technique. Recently, we introduced a commercial CLYC system in Korea, and performed an initial characterization and simulation studies for the CLYC detector system to provide references for the future implementation of the dual-mode scintillator system in various studies and applications. Materials and Methods:We evaluated a CLYC detector with 95% 6 Li enrichment using various gamma-ray sources and a 252 Cf neutron source, with validation of our Monte Carlo simulation results via measurement experiments. Absolute full-energy peak efficiency values were calculated for gamma-ray sources and neutron source using MCNP6 and compared with measurement experiments of the calibration sources. In addition, behavioral characteristics of neutrons were validated by comparing simulations and experiments on neutron moderation with various polyethylene (PE) moderator thicknesses. Results and Discussion:Both results showed good agreements in overall characteristics of the gamma and neutron detection efficiencies, with consistent ~20% discrepancy. Furthermore, moderation of neutrons emitted from 252 Cf showed similarities between the simulation and the experiment, in terms of their relative ratios depending on the thickness of the PE moderator.Conclusion: A CLYC detector system was characterized for its energy resolution and detection efficiency, and Monte Carlo simulations on the detector system was validated experimentally. Validation of the simulation results in overall trend of the CLYC detector behavior will provide the fundamental basis and validity of follow-up Monte Carlo simulation studies for the development of our dual-particle imager using a rotational modulation collimator.

Digital n-γ Pulse Shape Discrimination in Organic Scintillators with a High-Speed Digitizer

“…This shows that PSD performance can be substantially affected by the determination of the threshold. Optimized variables for two digital PSD methods can provide reference values for developing a fast neutron/ gamma-ray dual-particle imager with the stilbene scintillator and the EJ-301 liquid scintillator as feasibility discussed in one of previous studies [10][11][12].…”

“…Depending on the time width of typical pulse signals being processed, one can achieve processible count rate of pulses up to 500 kHz, which exhibits an advantage over previous analog PSD systems. As a fundamental step for the development of a fast neutron/gamma-ray dual-particle imager [10][11][12], we took an initiative approach to implement a fast neutron/gammaray dual-particle measurement system with digital PSD using the stilbene crystal from Inrad Optics, and the EJ-301 liquid scintillator from ELJEN TECHNOLOGY combined with DT5730 of CAEN. In the development of the fast neutron/ gamma-ray dual-particle imager, we take a single non-position-sensitive detector-based approach to obtain temporal modulation patterns determined by the rotating collimators.…”

Dual-Particle Imaging Performance of a Cs2LiYCl6:Ce (CLYC)-Based Rotational Modulation Collimator (RMC) System

“…In our previous study, the CLYC detector was characterized for its energy resolution and detection efficiency. Detailed information on the CLYC detector and the fabrication of the CLYC-based RMC system is elaborated in our previous work [25,26]. The CLYC detector utilized in our work showed a PSD figure of merit (FOM) of 3.1 using an energy window around the thermalneutron peak.…”

Characterization of a CLYC detector for underground experiments

“…The response function of the CLYC detector to γ-rays has ben calculated by Monte Carlo simulations with GEANT4 (release 10.03.p01). The GEANT4 toolkit was preferred over other simulation codes used in previous works [12,13] because of its built-in nuclear decay models (G4RadioactiveDecay) based on evaluated nuclear data libraries (ENSDF [14]) and its versatility for simulating complex decay schemes with correlated particle emission. This was of advantage in a first set of simulations aimed at reproducing the experimental measurements with standard γ-ray sources.…”