Simulating high-intensity proton beams in nonlinear lattices with pyorbit

High-intensity proton linacs and storage rings are essential for a) state-of-the-artneutron source user facilities, b) extending the high-energy physics intensity frontier, c)as a driver to generate pions for a future neutrino factory or muon collider, and d) fortransmutation of radioactive waste and associated energy production. For example, Project Xat Fermilab will deliver MWproton beams at energies ranging from 3 to 120 GeV. Nonlinearmagnetic lattices with large tune spreads and with integrable, nearly integrable andchaotic dynamics have been proposed to maximize dynamic aperture and minimize particleloss. We present PyORBIT simulations of proton dynamics in such lattices, including theeffects of transverse space charge for the first time.