Multi-Component Study of Extensive Air Showers at the Tien Shan Mountain Station of LPI and Peculiarities of the Particles Flux Behavior in the Central Region of the (1–100) PeV EAS

New multipurpose experimental complex of the Tien Shan mountain cosmic ray station of LPI incorporates a set of detector subsystems for simultaneous investigation of the various components of extensive air showers (EAS) which arise from interaction of the (1–100) PeV cosmic ray particle in the atmosphere. A wide-spread system of the charged particles detectors is used for the measurement of the local density of EAS electrons, and for estimation of the main EAS parameters by spatial distribution of this density. The radio-antennas and Cherenkov detectors provide an alternative way for investigation of the EAS electron component. The ionization-neutron calorimeter and the neutron monitor give information on EAS hadrons with the energy above 0.1 TeV, while the low-threshold neutron and gamma detectors can be applied for registration of the prolonged flux of thermalized neutrons and soft gamma rays after EAS passage. The underground muon detector is used for investigation of the muonic component of cosmic rays in an exclusively wide range of muon energies, starting from 5 GeV, and up to tens and thousands of TeV, and with estimation possibility of the energy of muon. The multi-component technique practiced now at the Tien Shan station permits to study effectively those aspects of high energy cosmic ray interaction which have been never considered in previous experiments. In particular, it is possible now to adequately register the flow of various EAS components in the very region of EAS core which opens a real opportunity to solve the long-standing problem of the 3-PeV knee in the energy spectrum of cosmic rays. Some examples of the physical results gained lately at the Tien Shan detector complex are presented here for performance illustration of the newly elaborated methods of EAS investigation.