Dynamics Design on 70-250Mev Proton Linac

Charged proton beams have broad application prospects, and research on compact S-band proton linear accelerators is increasingly heating up in recent years. For radiation therapy, to achieve the conventional penetration range of water-equivalent tissues, protons with energy of 70 to 230MeV are required. The design of electromagnetic structure is closely related to particle dynamics design. A flexible and controllable particle dynamic tracking code (PDT) through both traveling wave and standing wave acceleration has been compiled to simulate particle trajectory and satisfy automatic tuning of the various components in the entire acceleration chain. The linac with a total length of approximately 8.2m composed of 16 tanks of backward traveling wave structures and permanent magnet quadrupole lenses was designed, operating at an RF frequency of 2.856GHz with a target acceleration gradient of 30MV/m, and accelerating proton beam from 70MeV to 250MeV while maintaining low emittance and high transmission efficiency.