High-Energy Events Registration System of Space-Based Gamma-Ray Telescope

We present a description of the design and main results obtained from measurements with a prototype of the high-energy event registration system of the space-based gamma-ray telescope on the positron beam of the S-25R "Pakhra" synchrotron at the Lebedev Physical Institute of the Russian Academy of Sciences. The prototype includes an anticoincidence and time-of-flight systems, a pre-shower detector and a calorimeter based on BC-408, BGO and CsI(Tl) scintillators with appropriate front-end and processing electronics. Silicon photomultiplier matrices were used as photosensors in all scintillation detectors of the prototype.