基于虚拟样机的回旋加速器主磁铁设计与修正

摘要

磁铁设计对于等时性回旋加速器极为关键.磁场分布需要满足粒子等时性加速和粒子径向、轴向聚集要求,同时避免危险的横向共振.提出了一种计算机辅助的自动化磁铁设计、建模和修正的方法,该方法在基于Python混合编程的虚拟样机集成设计环境中实现.详细描述了利用3维电磁场仿真软件TOSCA和自主开发的粒子束跟踪软件PTP对磁铁的优化过程,并给出了一个16 MeV负氢紧凑型回旋加速器的主磁铁设计实例.%Magnet design and modeling is a crucial task in the design of cyclotrons, which includes iterative processes from an initial model. The magnetic field distribution should fulfill the requirements of isochronisms and transverse focusing of the beam, as well as avoiding dangerous resonance crossing. This paper introduces an automated magnet design, modeling and shimming method under the pythonic integrated environment based on virtual prototyping, a novel technique to shorten development period and reduce costs for physical prototypes. Detailed magnet shimming processes with the support of the 3D magnetic field simulation code TOSCA and an original developed particle tracking code PTP are described. As a case study, the main magnet design of a 16 MeV H- compact isochronous cyclotron is illustrated and validated in a virtual prototype.