摘要
深圳中能高重频自由电子激光装置(S3FEL)是一台规划中的软X射线自由电子激光(FEL)装置,基于TESLA(TeV Energy Superconducting Linear Accelerator)型超导射频腔的直线加速器用于获得高重频高梯度的加速场,超导射频腔所在的低温超导模组是S3FEL装置中最具挑战的核心设备。超高真空差分段位于低温超导模组束流管出口,用于实现电子束运行管道在低温模组段与常温段的过渡,同时差分段上要求具有真空联锁保护,用于在突发情况下对低温模组内超导射频腔的保护。传统的快速关闭阀保护计算中仅按照气体分子速率进行计算,本文通过根据流态判据,划分快阀传感器至模组出口区域并开展有限元法和蒙特卡罗法计算,实现快速保护过程的瞬态分析。快阀传感器—快阀段真空室内瞬态压强分布计算结果表明,快阀传感器设置在距离快阀8~10 m位置可提供足够的缓冲反应时间,使快阀有足够时间做出动作响应;差分段瞬态压强分布计算中,当发生等效泄漏尺寸为0.5 mm的突发泄漏时,当低温测门阀完全关闭时,此处的压强最高达到10-5 Pa,仍能维持较好的高真空环境并满足离子泵的工作要求。此工作为S3FEL的差分段设计提供重要理论依据。
[Background]Shenzhen Superconducting Soft X-Ray Free Electron Laser(S3FEL)is a facility newly proposed by Institute of Advanced Science Facilities,Shenzhen(IASF).The linear accelerator based on a TESLA-type superconducting RF cavity is used to obtain a high-repetition-frequency and high-gradient field.The cryomodule is the most challenging core part of the S3FEL device and ultra-high vacuum differential system is located at the module beam pipe outlet,which is used to realize the transition from cryomodule to ambient temperature section.The vacuum interlock protection is required for the differential system to protect the superconducting RF cavity in cryomodule from emergencies.[Purpose]This study aims to analyze the transient process of rapid protection.[Method]The traditional fast closing valve protection process is only calculated according to the gas molecular rate.In this paper,the finite element method and the Monte Carlo method are used in this paper.[Result]The transient pressure distribution results of sensor-fast closing valve section show that setting the sensor 8—10 m away from the fast closing valve can provide sufficient buffer reaction time.[Conclusions]The differential system analyses show that the pressure here reaches 10-5 Pa within 2 s when the gate valve is completely closed,corresponding to a leakage size of 0.5 mm,which still maintains a high-vacuum environment and meets the working requirements of ion pumps.This work provides an important theoretical basis for the S3FEL.
作者
常仁超
尉伟
赵峰
朱潇潇
张浩
Chang Renchao;Wei Wei;Zhao Feng;Zhu Xiaoxiao;Zhang Hao(Institute of Advanced Light Source Facilities,Shenzhen 518107,China)
出处
《强激光与粒子束》
北大核心
2025年第12期64-71,共8页
High Power Laser and Particle Beams
基金
深圳市科技计划项目(JCYJ20220530140807017)。
关键词
自由电子激光
高重频
差分段
真空联锁保护
有限元分析
free electron laser
high repetitive frequency
differential system
vacuum interlock protection
finite element analysis
