上海光源超导波荡器模型机失超保护设计

Quench protection for a superconducting undulator prototype at the SSRF

中国科学院上海应用物理研究所正在研制一台50周期的低温超导波荡器模型机用于上海同步辐射光源装置,磁体绕组采用NbTi超导线,周期长度16mm,磁间隙9.5mm,运行电流为400A,目标峰值磁场0.67T。磁体储能为7.2kJ。为了保证模型机安全稳定的运行,采用基于有限元方法的数值模拟,将50周期磁体简化为绕组模型并分析其失超过程,根据实验与分析结果提出失超保护设计方案。将50周期磁体的上下两部分作为两段,每段通过失超探测仪进行监测,并通过并联背靠背的冷二极管进行保护。为了使设计尽可能简化并限制磁体端部电压,没有采用主动加热器与引能电阻。

Shanghai Institute of Applied Physics, Chinese Academy of Sciences is developing a superconducting undulator prototype for the Shanghai Synchrotron Radiation Facility （SSRF）. The 50 -period prototype is composed of NbTi coils. The period length is 16mm. The magnetic gap is 9.5mm. The operating current is 400A to produce a peak field of 0.67T on axis. The stored energy is 7.2kJ. Quench analysis was performed on a simplified model via numerical simulation based on finite element method. A quench protection scheme was proposed based on the experimental and simulation results. The magnet is subdivided into 2 sections and monitored using a quench detector. Each section is protected by cold diodes. Heaters and shunt resistors are not adopted for simplification and to limit the voltage of magnet ends.