The search and analysis of optimal criteria for the selection of extensive air showers from γ -quanta by Cherenkov telescopes

Here is proposed, analyzed and substantiated a technique for selecting extensive air shower (EAS) from ultrahigh-energy gamma quanta against the background of protons by using angular Cherenkov telescopes. A concrete version of the configuration of optical detectors for recording EAS Cherenkov light (CL) and methods of processing their data and the achievable accuracy of separating gamma quanta against the background of protons are presented. The mechanism of operation of the criteria in the range of primary energies of 30–100 TeV is also described. The criterion separating the two classes of events is formed of the integrals of the measured angular distribution of EAS Cherenkov light over certain solid angles. The Cherenkov light spot seen by the telescope is related to the optical cascade curve of the EAS. This technique was developed within the framework of the "Pamir-XXI" project, but it can be useful both for other high-altitude projects, and for the EAS method in general.