CsI and SrI₂(Eu) Scintillation Detectors with Signal Removal by Silicon Photomultipliers with a Registration Threshold Below 200 eV

The article discusses the concepts of detectors made of inorganic scintillators CsI(pure) and SrI₂(Eu) with light signal removal by silicon photomultiplier matrices. These detectors are supposed to be used at low temperatures to register signals with ultralow energy release. The results of measuring the light collection of detector prototypes are presented. Specific light collections were obtained at the level of 30–40 photoelectrons per kiloelectronvolt of energy released in the detectors. The dependences of thermal noise and optical coupling of silicon photomultipliers on temperature are investigated. It is shown that the use of detectors at negative temperatures makes it possible to effectively suppress the noise of photodetectors and provide a registration threshold at the level of several photoelectrons. These detectors can be in demand in various fundamental and applied fields, in particular, in the physics of low-energy neutrinos.