The study of cosmic rays with a wide-angle Cherenkov telescope

Abstract

This report presents an observation method of Cherenkov light from extensive air showers (EAS) generated by cosmic rays (CRs) above 10 16 eV and preliminary observations. The interest in Cherenkov light differential detectors of EAS is caused by the possibility to measure the depth of cascade maximum, Xmax, and/or the shower age via angular and temporal distributions of the Cherenkov signal. In particular, it was shown using EAS model simulations that the pulse width measured at the periphery of the shower, r > 300 m, at sea level is pronouncedly connected with Xmax. Cherenkov detector is a wide-angle telescope working in coincidence with scintillation detectors, integral and differential Cherenkov detectors Yakutsk complex EAS. This provides the data on lateral distribution of photon intensity and total flux of Cherenkov light in EAS. The detector is located near (about 2m) with one of the integral Cherenkov detector. This detectors signal was calibrated using plastic optical radiator. So, we have a possibility to normalize an integral signal from telescope to that of the Cherenkov detector. We have completed the field testing of the prototype wide FOV telescope. A number of EAS events are detected in coincidence with the surface detectors of the Yakutsk array. A detection efficiency of the telescope is measured as well as the effective radius of the telescope detecting area. The report details the technical specifications of the telescope, as well as the results of the first experimental observations.