Multimodal EAS events with energies $10^{16} − 5\times10^{18}$~eV according to Corsika data at the level of the Tien Shan station (3346m)

In various experiments where Extensive Atmospheric Showers (EAS) are recorded, EASs with an unusual, “multimodal” temporal structure are observed - several pulses separated in time by several hundred ns are recorded at the installation detector modulars. In this work, the task was to demonstrate the possibility of multimodal events at the detector points of the Horizon-T installation, located at the Tien Shan high-mountain station of the Lebedev Physical Institute at an altitude of 3346 m above sea level without the involvement of exotic particles and processes. Simulation based on the commonly used Corsika code with nuclear interaction model QGSJET. It was assumed that several particles or groups of particles from one EAS, separated by a significant time, enter the detector’s time gate, which leads to the formation of a sequence of several pulses. This hypothesis was successfully confirmed by modeling ultra-high energy EASs from $10^{16} − 5\times10^{18}$~eV close to vertical (up to 30 deg) and highly inclined (from 30 up to 70 deg).