Muons in Extensive Air Showers with Energy above 10 17 eV According to the Long Standing Studies at the Yakutsk Array

lateral distribution of muons was studied in extensive air showers initiated by cosmic rays with energy above 1017 eV. The study is based on the experimental data of underground scintillation detectors with 1-GeV energy threshold collected during the continuous observational period lasting from 1986 to 2017. Experimentally measured values of muon density are compared to results of simulations performed for primary protons and iron nuclei within the framework of four ultra-high energy hadronic interaction models. The density of particles with 1-GeV threshold obtained in simulations was then converted to the signal of ground-shielded scintillation detectors of the array. Studying the features of the resulting muon lateral distribution has allowed us to reconstruct parameters of longitudinal development of extensive air showers.