MARS simulations of the NuMI primary beamline

MARS is a Monte Carlo code for simulation of three-dimensional hadronic and electromagnetic cascades, muon and low-energy neutron transport in shielding and in accelerator and detector components in the energy range from a fraction of an eV up to 100 TeV. This report uses MARS to both transport the 120 GeV primary proton beam from the NuMI extraction Lambertsons through the NuMI Pre-target Hall and calculate the radiological effect of beam losses at various locations and for a variety of conditions. These results are used to: anticipate where beam losses will be significant; determine the level of activation of components; and calculate ground water activation and confirm adequacy of shielding. The results are presented in tables and figures along with drawings of the magnets as they were modeled in MARS. Details of the model elements are found in Appendix A. Further details of beam loss case studies are included in Appendix B.