Instruments for detecting the unsanctioned displacement of radioactive materials

In 2006, gamma-ray detector, consisting of the number of parallel scintillation units with BGO crystals was theoretically developed by the group of environmental radioactivity from Lomonosov Moscow State University. High effective atomic number of BGO and the selected detector geometry contributes to the effective registration of gamma-quanta, which enter mainly in parallel to the symmetry axis of the system. It is shown that the realization of detector as a whole will make it possible to check gamma-ray emitters in vehicles and to solve other problems connected with the prevention to terrorist actions. Some promising trends of the detectors developed for low level activities are examined.