用于质子治疗的紧凑型旋转机架设计与关键技术研究

基于质子束独特的布拉格峰剂量分布特性，质子治疗可实现对周边组织损伤更小的精准肿瘤放疗，是当前先进的放射治疗方法。旋转机架可实现多角度质子束照射，是质子治疗装置的核心部件之一。采用常温磁铁的机架束线是当前的主流方案，但存在重量及体积偏大的问题，机架总重通常超过200吨；采用超导磁体技术的轻量化机架是未来发展趋势及当前国际研究热点。本项目提出的基于交变梯度组合超导二极磁体的机架方案，结合局部消色散束流光学设计，可将机架束线动量接受度提高至+/-10%以上的水平，克服了超导磁体难以快速改变磁场的技术难点。项目拟针对该轻量型机架方案完成高阶束流光学设计，开展交变梯度超导磁体设计及相关关键技术研究，在此基础上完成一套完整的紧凑型质子治疗机架工程技术方案，为其工程实现奠定基础。

Due to the unique 'Bragg peak' dose distribution characteristics of the proton beam, the proton therapy (PT) is recognized as one of the most precise and effective radiotherapy method for tumors. The rotation gantry is a crucial equipment of PT facility, which is capable to project the proton beam on tumors with various angle for multiple-field irradiation. The gantry beamline using resistive magnets is the main scheme for present PT facilities. However, the overall weight of resistive gantries normally exceeds 200 tons, with contribution mainly from dipoles and large scale footprint. Light weight superconducting gantry becomes a future trend and research hot spot in world wide. This project proposed a light weight gantry scheme based on alternating gradient (AG) combined function superconducting dipoles. By employing local dispersion suppression, the momentum acceptance can be increased to the level of +/-10%, which overcomes the technical difficulty of fast magnetic field change in superconducting dipoles. This project will focus on high-order optics design of gantry beamline, design and technical research on AG superconducting magnets. Finally, a complete technical design and solution will be implemented.