A gamma-ray detector with a silicon photomultiplier (SiPM) readout for neutron diffraction experiments at spallation neutron sources

摘要

Standard detectors for neutron diffraction experiments are typically ~(3)He filled proportional counters. Indeed, in the near future the ~(3)He availability will be greatly reduced, so the R&D activity on alternative neutron counters is a very important issue to be addressed. Scintillator detectors could be considered as one of these alternatives. In this context, a prototype thermal neutron counter composed of a yttrium-aluminium-perovskite scintillator crystal coupled to a silicon photomultiplier (SiPM) and a standard photomultiplier tube (PMT) was used in time of flight neutron diffraction experiments on the INES spectrometer at the ISIS spallation neutron source. Neutron detection was realized by attaching the crystal to a natural cadmium sheet, used as a (n, gamma) converter. Results show that the SiPM-based readout detection system has promising performances with respect to that based on a standard PMT. Diffraction patterns recorded with the ~(3)He tubes' neutron counters in use on INES allowed a comparative assessment of the SiPM-based device for time of flight neutron diffraction experiments, with respect to the standard detection technique.