Increases in the Gamma-Ray Background: General Properties and Statistical Characteristics

A special system is designed and produced at the Polar Geophysical Institute to monitor the soft gamma radiation induced by cosmic rays in the atmosphere. The radiation is registered in two ranges: 20−400 keV and 0.2−0.8 MeV. Monitoring begins in 2010 at cosmic-ray stations at Apatity and Barentsburg (Spitsbergen Archipelago). A new phenomenon is discovered at the start of observations: the gamma background grows during precipitation. At the same time, no radionuclides are found in the precipitates. The large volume of data on these increases allows analysis of them and identification of their characteristic features