Evaluation of angular dependence of neutron detection efficiencies of ZnS scintillator detectors

The detection efficiencies of ZnS neutron-sensitive scintillator detector were evaluated as functions of the neutron incidence angle on the scintillator and neutron wavelength using a pulsed neutron beam that generates neutron with wavelengths from 0.5 to 8 Å. ZnS/⁶LiF and ZnS/¹⁰B₂O₃ scintillator screens with thicknesses of 0.45 and 0.22 mm, respectively, were used for the evaluation. The detection efficiency of each scintillator was strongly influenced by the incidence angle and the neutron wavelength. A fitting model that incorporates both the neutron-absorption and light-escape probabilities reproduced the measured detection efficiencies very well.