Prototype of Position-Sensitive Scintillation Neutron Detector Based on SiPM and ZnS:Li6

A prototype for a new position-sensitive scintillation neutron detector based on silicon photomultipliers and organic glass is described. The method of separation and attenuation of photons in the volume of the light guide is used as a method for determining the region of particle detection. A description of a similar method for determining the coordinates of the point of particle entrance into the detector is given. Optical simulation of the propagation of photons in the scintillation detector is performed, and the numbers of photons for various types of reflective surfaces (diffuse or mirror surfaces) are simulated and compared. According to the simulation results, the diffuse reflector shows a higher photon-separation factor, which can be used to extract the coordinate. In addition, the diffuse reflector shows more photons incident on the silicon photomultipliers. A prototype scintillation detector with one scintillator layer and two silicon photomultipliers at the edges is designed on the basis of the model. A ZnS(Ag):Li 6 layer with an efficiency of 42% and a size of 5 × 50 mm is used as the scintillator. Plexiglas with a transmittance of 92% is used as the light guide. The surface of the light guide is wrapped with Fluoroplast-4 tape, which serves as a diffuse reflector. The dimensions of the finished detector are 5 × 5 × 60 mm. The tests of the detector demonstrate the possibility of extracting coordinates with two silicon photomultipliers. The resolution estimate of the obtained detector approximately equals 6.25 mm.