Forward physics with the ATLAS detector

Very high-energy proton-proton interactions, and collisions of light and heavy ions are foreseen at the LHC. Proton beams will have an energy corresponding to 10/sup 17/ eV in the rest frame of target protons, almost approaching the highest energies observed in cosmic rays. In this range, accelerator data may help to answer questions about the primary cosmic ray composition and the cross sections of the very high energy cosmic rays on air. ATLAS is undertaking a program of elastic and diffractive physics, which overlaps the interests of the cosmic ray community. The ATLAS collaboration invites inquiry, ideas, and collaboration from the cosmic ray community in developing this program. (7 refs)