FECR超导离子源Nb3Sn磁体半长度样机的结构分析

Mechanical design of the half-length prototype for a superconducting FECR ion source

摘要:

中国科学院近代物理研究所正在研制运行于45GHz的世界首台第四代电子回旋共振离子源FECR(Fourth Electron Cyclotron Resonance)。该离子源磁体线圈全部采用Nb₃Sn(铌三锡)超导材料制作、这一超导材料临界性能对应力敏感,加之磁体中六极线圈和螺线管线圈之间的应力不平衡分布,导致磁铁机械结构设计面临极大挑战。为了验证离子源磁铁结构设计的合理性和仿真结果的可信性,为全尺寸真机的研制奠定技术基础,设计了能够一定程度上反映离子源磁体机械结构的半长度样机。本文主要介绍了FECR半长度样机的三维机械结构设计,借助ANSYS有限元软件分析了磁铁在室温组装、冷却降温和加电励磁时的应力分布和变化情况,为磁体装配提供关键的预应力参数。

Abstract:

The new Nb₃Sn superconducting magnet system for the fourth-generation 45GHz ECR source(FECR) is under developing in the institute of Modern Physics (IMP). Because the magnet is made from Nb₃Sn which is sensitive to the strain and there are strong Lorentz forces between the solenoids and sextupole coils, the mechanical structure design is a big challenge. In order to validity the reasonability and feasibility of the structure design and its simulation results, a half-length prototype of the FECR magnet was developed.This paper presents the detailed design of the magnet structure. The stress distribution and variation of the prototype during assembly,cooling down and charging have been got with the three-dimensional finite-element model and are presented in the paper. The results will be used as reference of the room-temperature magnet assembly.