Neutron scintillators with high detection efficiency

We have developed three kinds of phosphor/neutron-converter scintillators aiming to increase the detection efficiency of the neutron imaging detectors. One is the ZnS:Ag/6LiF (powder) scintillator, which contained 6LiF about twice in amount comparing to the commercial product (Bicron, BC-704) and painted in a sheet, and the 0.4-mm-thick scintillator sheet exhibited the detection efficiency of 43.5% for thermal neutrons. This value was improved ∼1.5 times than that of BC-704. Another developed scintillator was a ZnS:Ag/10B2O3 (powder), which contained 10B as a neutron converter. The scintillator was fabricated by sintering up to the temperature of 500 or 600°C, and it exhibited the detection efficiency of 30% for thermal neutrons. Moreover, we developed ZnS:Ag/10B2O3 glass-scintillator, which was fabricated by increasing the amount of 10B2O3 up to 70–90% of the constituents and by sintering the scintillator materials up to the temperature of 650°C. The fabricated glass scintillators, which had a thickness of 0.9–1 mm, exhibited the detection efficiency of 20–40% for thermal neutrons.