230 Mev医用回旋加速器主磁铁的设计

Design of 230 Mev Main Magnet for Medical Cyclotron

摘要: 质子治疗作为一种新的肿瘤放射治疗手段有着比常规γ射线和X射线治疗定位更精准、正常组织受损更小、治疗适应症更广、并发症少等优点。而加速器是质子治疗系统最重要的设备之一，因此对加速器做相关设计研究具有重要的实际意义。磁铁是回旋加速器的关键部件，磁铁的设计直接关系着加速器的工作性能，磁铁设计的各项内容是密切相关的，本设计过程基于磁路原理，可根据所需的具体要求来选择基本的电磁参数并以此计算出主磁铁的几何结构参数。本文以用于质子治疗的230 Mev回旋加速器的主磁铁为例，介绍了常规的医用回旋加速器设计流程，应用有限元分析软件ANSYS对主磁铁进行了二维下的磁场分析，得到了主磁铁的磁场分布，仿真结果表明设计的主磁铁在峰区中平面的磁密能达到1.72 T，在谷区中平面磁密能达到0.2 T，可满足对粒子的加速。

Abstract: Proton therapy, as a new radiotherapy method for tumor, has the advantages of more accurate lo-calization, less damage to normal tissue, wider indications and fewer complications than conven-tional γ-ray and X-ray therapy. The accelerator is one of the most important equipment in proton therapy system, so it is of great practical significance to design and study the accelerator. Magnet is a key part of cyclotron, the design of magnet is directly related to the working performance of the accelerator, the content of magnet design is closely related, this design process is based on the prin-ciple of magnetic circuit, according to the specific requirements to select the basic electromagnetic parameters and calculate the main magnet geometric structure parameters. In this paper, used for proton therapy of 230 Mev cyclotron magnet as an example, the main conventional medical cyclo-tron design process is introduced, the application of finite element analysis software ANSYS under the main magnet in the two-dimensional magnetic field analysis, the main magnet of the magnetic field distribution, the simulation results show that the design of the main magnet in the peak dis-trict in the plane of flux density can reach 1.72 T, In the valley region, the plane magnetic density can reach 0.2 T, which can meet the acceleration of particles.