A newly observed phenomenon in the characterisation of SiPM at cryogenic temperature

In this article we report a novel phenomenon that we observed while evaluating the performances of different models of silicon photomultiplier detectors at liquid nitrogen temperature. Bursts of consecutive events, characterized by a rate that is about 100 times that of the single-event uncorrelated dark counts, are generated within the SiPMs, resulting in an overall increase of the dark current. We observed these bursts in the vast majority of the tested SiPM models manifactured by Hamamatsu Photonics K.K. This observation is part of an effort to fully characterise the behaviour of SiPMs at cryogenic temperature. The investigation of this phenomenon, of which a first attempt is presented in this article, can impact future production and selection of models for both high energy physics and industrial applications.