强背景磁场下分子泵磁屏蔽体的设计与研究  

Design and Research of a Magnetic Shield for Turbo-Molecular Pump under Strong Stray Magnetic Field

作　　者：朱晓锋 张素平[1] 关镭镭 潘高峰[1] 王胜龙 张天爵[1] ZHU Xiaofeng;ZHANG Suping;GUAN Leilei;PAN Gaofeng;WANG Shenglong;ZHANG Tianjue(Research and Design Center of Cyclotron,China Institute of Atomic Energy,Beijing 102413,China)

机构地区：[1]中国原子能科学研究院回旋加速器研究设计中心,北京102413

出　　处：《真空科学与技术学报》2021年第12期1130-1135,共6页Chinese Journal of Vacuum Science and Technology

摘　　要：中国原子能科学研究院目前正在研制一台230 MeV超导回旋加速器,该回旋加速器未来是安装于医院应用于质子治疗,采用了非常紧凑型的超导磁体结构设计。其分子泵所安装位置有非常大的漏磁场,其漏磁场强度达到1000 Gs,是分子泵安全运行阈值(50 Gs)的20倍,导致分子泵不能正常工作。为了解决这个问题,首先进行了分子泵磁屏蔽体的结构设计,以及3D有限元仿真分析计算,然后开展对不同分子泵磁屏蔽体内的磁场进行详细测量,结果表明磁屏蔽体内部的剩磁场均小于50 Gs,且分子泵实际长时间运行过程中监测分子泵运行参数电流、轴承温度、转子温度、加速时间均与无磁场时运行参数一致。Currently,a 230 MeV superconducting cyclotron is under development at China Institute of Atomic Energy.The superconducting main magnet of this cyclotron is optimized to be ultra-compact to be installed in the hospital,thus inevitably has larger magnetic leakage at the turbo pump installation ports,where the magnetic flux density reaches 1000 Gauss,which is 20 times larger than the turbo pump’s safe operation limit(within 50 Gs).This may further cause the malfunction of the turbo pumps.To solve this problem,a sophisticated magnetic shielding is designed using a 3 D FEM model.Then a careful measurement of the magnetic flux density after shielding is performed,and the results show that the residual field within the shielding is limited below 50 Gauss.Further monitoring of the turbo pump operation parameters,like the driving current,the temperature of the turbo bearing,etc.,show a good agreement with the non-magnetic working condition.

关 键 词：真空系统 磁屏蔽 分子泵 剩磁场 

分 类 号：TL542-1[核科学技术—核技术及应用]