Measuring the energy spectrum of primary cosmic rays with the Yakutsk EAS array

The Yakutsk Extensive Air Showers (EAS) array was designed for detecting the showers generated by the 10 to the 47th power to 10 to the 20th power eV primary cosmic rays and consists of numerous electron, muon, and Cerenkov light detectors arranged on a 20 sq km area terrain. The array is featured by the feasibility to detect the EAS-produced Cerenkov light, hence, as will be shown, to find the mean energy of the primary particles generating an ensemble of EAS of given size. Date collected is discussed.