Detection of 10 to 300 keV fast neutron using CLYC, CLLB and CLLBC scintillators

Abstract The neutron and gamma detection performance of multimode scintillators including Cs 2 LiYCl 6 :Ce (CLYC), Cs 2 LiLaBr 6 :Ce (CLLB) and Cs2LiLaBr 6-, x Cl x :Ce (CLLBC) were tested in this work. The energy resolution for 662 keV gamma rays was 4.19% for CLLB, which was better than that of 4.80% for CLLBC and 5.27% for CLYC. The Figure of Merit value (FOM) was used to evaluate the neutron/gamma-ray (n/ γ ) discrimination capability, which was 2.2 for CLYC, superior than that of 1.3 for CLLBC and 1.1 for CLLB. A method for fast neutrons detection within the energy order of 100 keV was proposed, which could be realized using the 6 Li(n, α )T reaction by the fact that the peak centers are sensitive to the incident neutron energy. This was validated by test the energy spectra of CLYC using an Am-Be source with various paraffin moderator, where the peak centers of the energy spectra were found to decrease linearly with the paraffin thickness. The Monte-Carlo simulation was conducted to prove the average neutron energy decreased linearly with the paraffin thickness and the energy spectra results were consistent with the experimental results. It could be concluded that 6 Li enriched CLYC (CLLB or CLLBC) could be used to detect fast neutrons in the energy range of 10–300 keV, which further expand the application range of CLYC for multimode neutron gamma detection.