We have built a Monte Carlo generator for simulating propagation of cosmic ray particles in the atmosphere. The core of the generator is a $p$-air nuclear interaction model in which SD and NSD processes are included in the inelastic collisions. Based on QCD partonic theory, multiple minijet production is described in detail in the NSD process. A phase-space model is used for the SD process in our work. This generator reproduces cosmic ray experimental data well at very high energies.

• Received 2 July 1996

DOI:https://doi.org/10.1103/PhysRevD.55.5657