Pulse shape discrimination of CLYC scintillator coupled with a large SiPM array

This paper discusses measurements performed to evaluate the possibility to build a neutron probe based on a CLYC scintillator coupled with a large SiPM array. The use of a large SiPM array allows optimizing the light collection, necessary for spectrometry. However, a large SiPM array leads to huge capacitance, whose main impact is to slow down the input signals. Therefore, pulse shape discrimination (PSD) is lost due to the electronic process. To solve this problem, an electronic board was designed to extract the fastest scintillation decay times from the crystal without cutting the crystal response. The impact of using a large SiPM array instead of a PMT is evaluated by comparing the PSDs and the scintillation decay times. A figure of merit (FOM) of 2.3 was found with the SiPM versus a value of 2.64 for the PMT. In addition, the neutron efficiency was measured and compared to the one simulated with the MCNP code. The angular dependence and the linearity range in dose rate were also evaluated.