The overall goal of this Fast Track project is to combine innovations in superconducting magnet design and new magnet topologies to create a lightweight toroidal beam bending magnet for rotating gantries used in proton beam therapy. The magnet is robust for pencil-beam scanning therapy, as the magnet is dry (no liquid helium coolant) and can withstand AC losses from rapidly varying magnetic fields (needed for varying the energy of beam to adjust penetration of the beam into the tumor). This toroidal bending magnet will use a unique, cryogen-free self- shielded superconducting magnet that makes the scanner attractive for pencil beam scanning using a proton beam. The proposed bending magnet uses an innovative magnet topology that is constant field along the beam and self-shields the magnetic field, eliminating the need and weight of the iron. The combination of proven technologies in design and manufacturing of high-field (1.5T and higher) cryogen- free MRI magnets and the innovative constant-field toroidal field beam bending magnet results in a significant breakthrough gantry design.
In hadron (proton or carbon) beam therapy, the gantry is a substantial and, is some cases, dominant fraction of the cost of the system. Reducing the weight, size and power consumption could substantially reduce the installation cost and ease of maintenance. Recent studies have shown the utility of proton beam therapy for some types of cancers, but increase use will depend on the economics. The overall goal of this project, Phase I and II combined is to explore the potential for decreased gantry costs by combining innovation in superconducting magnet design and a new magnet configuration to design and test a lightweight, compact, self-shielding inexpensive beam bending magnet.
