Nucleus-nucleus collisions and interpretation of cosmic-ray cascades

We describe a multiple scattering model of nucleus-nucleus collisions for use in simulation of atmospheric cascades produced by high-energy cosmic-ray nuclei. We emphasize the importance of a realistic treatment of nuclear fragmentation of the incident nucleus for fluctuations in quantities such as high-energy muon bundles and longitudinal development of giant air showers. The model is realized in a cascade program that can be combined with any treatment of hadronic interactions.