Simulation study on the characteristics of secondary cosmic ray with LHAASO

Abstract:

The Large High Altitude Air Shower Observatory (LHAASO) is located at Haizi Mountain in Daocheng County (4400 m a.s.l., Sichuan, China). This experiment is realized by using various methods for an accurate duplex measurement on the secondary cosmic rays entering the atmosphere. The thunderstorms occur frequently in high altitude areas, so the number, direction and energy of secondary particles of cosmic rays in the Extensive Air Shower (EAS) will be affected by thunderstorms electric field. In this paper, employing Monte Carlo method, we simulate the process of EAS for the primary particles cosmic rays entering the atmosphere and study the longitudinal distribution, the lateral distribution and the energy distribution of photons, electrons and muons in the secondary particles. The results show that the number of electrons on the LHAASO detector surface is 2 ~ 3 times more than that of the muons; the muons have a wide range of horizontal distribution, while the electrons are of concentrated distribution; the muon's energy is much larger than that of the electron. Considering the influence of the electric field, the effect of the electric field will be more evident on the electrons, which has tiny mass. Our simulation results are significant in studying the acceleration mechanism of secondary charged particles caused by electric field and provide important information to understand the observation of ground experiments during thunderstorms.