عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Ultra-high energy cosmic rays (with energies above 1014 eV), by interaction with the atmosphere, generate cascades of particles (secondary particles) which increase in the atmosphere, depending on the level of penetration. Then they reach a maximum content. Following this stage, their numbers are decrease until they arrive at the surface detectors. In this paper, by using Yakutsk, Volcano Ranch and Haverah Park array data, where there are in the different altitudes, the amount of variation of secondary particles is discussed.