Estimation of the PCR mass composition in the energy range 10 17 –10 19 eV on the basis of multicomponent analysis of the characteristics of EASs detected at the Yakutsk array

The characteristics of longitudinal and radial extensive air shower development derived from the results of detection of the charged particle flux and Cherenkov light in extensive air showers at the Yakutsk array. To estimate the primary cosmic ray composition, a combination of the parameters X max and ρ 600 and the database simulated using the CORSIKA code (QGSJET model) for showers generated by five types of nuclei (p, He, C, Si, Fe) in the energy range 10 17 –10 19 eV were used. Application of the multicomponent method made it possible to divide the showers into three groups (p + He), C, and (Si + Fe) and estimate their percentage. The error in identifying nuclei in the energy range 10 17 –10 18 eV does not exceed 30%.