Cryogen-free Light-weight Superconducting Beam Bending Magnets for Proton Therapy

 描述(申请人提供)：这个快速通道项目的总体目标是结合超导磁体设计的创新和新的磁体拓扑结构，创造一种用于质子束治疗的旋转龙门的轻量级环形束流弯曲磁体。这种磁铁对于铅笔束扫描治疗是坚固的，因为磁铁是干燥的(没有液氦冷却剂)，并且可以承受快速变化的磁场(需要改变光束的能量以调整光束对肿瘤的穿透)造成的交流损失。这种环形弯曲磁体将使用独特的无低温自屏蔽超导磁体，使扫描仪对使用质子束的铅笔束扫描具有吸引力。建议的弯曲磁体采用了一种创新的磁体拓扑结构，即沿束方向保持恒定的磁场，并自我屏蔽磁场，从而消除了对熨斗的需要和重量。设计和制造高场(1.5T及更高)无冷源磁共振磁体的成熟技术与创新的恒场环向场偏束磁体相结合，实现了一项重大的突破性龙门设计。

 DESCRIPTION (provided by applicant): 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.