Implementation of muon interaction models in PHITS

We have constructed models for muon interactions (i.e., bremsstrahlung, electron- positron pair production, muon photonuclear interaction, and negative muon capture reaction) and implemented these models in the particle and heavy ion transport code system (PHITS). The PHITS2.86 agrees well with experimental data for the vertical intensities of cosmic-ray muons in water and standard rock. The calculated results for neutron production by muon photonuclear interaction and negative muon capture reaction are in good agreement with measured data, except in the case of lead target. PHITS2.86 can also reproduce the cross-section of radionuclide production by muons passing through a concrete wall very well. These results indicate the applicability of PHITS2.86 to the shielding design of muon facilities in which estimations of attenuation length and induced radioactivity are important.