Simulations of Rapid RF-Driven 3-D Proton Beam Scanning*

We investigate the design of a 2.856 GHz accelerator system to provide energy modulation and RF-based steering for rapid 3-D beam scanning for hadron therapy. Using General Particle Tracer, we simulate proton beam transport through the accelerator and deflector cavities. Field maps of the accelerating and deflecting fields in each section of the beam line are produced using ANSYS-HFSS models of the cavity geometries. Designs are optimized for the case of sub-relativistic protons with 230 MeV kinetic energy and cover an energy modulation range of ±30 MeV. We present beam profile data after transport to different transverse positions, achieved using a combination of dynamic RF deflector cavities and static permanent magnet quadrupoles. We discuss the beam profile aberrations introduced for large transverse deflections.