强激光与粒子束2025，Vol.37Issue(9)：60-68,9.DOI:10.11884/HPLPB202537.250024
一种RF屏蔽型CF法兰-密封圈结构设计
Design of RF shielding CF flange copper ring structure
摘要
Abstract
[Background]High-repetition-rate electron accelerators face beam instabilities induced by wake fields from beam-vacuum chamber interactions.Geometric discontinuities at ubiquitous con flat(CF)knife-edge flange connections are a dominant source of beam-induced impedance in all-metal vacuum chambers.[Purpose]To mitigate this impedance,this paper presents the design of an RF-shielded flange-gasket connection structure that achieves a smooth post-tightening transition at the interface,thereby minimizing impedance.[Methods]Electromagnetic simulation:3D simulations(CST)analyzed impedance effects of radial step heights and axial gaps at the transition,establishing allowable parameter ranges.Deformation simulation:ANSYS simulations modeled the shielded flange-copper gasket assembly to preliminarily determine inner diameter specifications for various gasket models.Vacuum sealing tests:Verified ultra-high vacuum integrity under applied tightening torque.Transition geometry testing:Measured the achieved radial step and axial gap post-tightening to define optimal copper gasket dimensions and tightening torque.Comparative simulation:CST simulations compared power loss and impedance for smooth chambers,standard flange-gasket transitions,and the proposed shielded transition.[Results]Electromagnetic simulations were used to define critical tolerance ranges for radial step and axial gap.Deformation simulations were utilized to provide initial gasket inner diameter specifications.Vacuum tests confirmed effective sealing at a tightening torque≥6 N·m.Transition testing established the optimal tightening torque and key copper gasket dimensions ensuring minimal geometric discontinuity.Comparative simulations demonstrated that the RF-shielded flange-gasket transition significantly reduces power loss and impedance compared to a standard CF transition,achieving performance close to that of a smooth vacuum chamber.[Conclusions]The designed RF-shielded flange-gasket connection structure effectively minimizes geometric discontinuity at the joint.Through combined electromagnetic,mechanical,and vacuum testing,critical parameters,including radial step,axial gap,gasket dimensions,and tightening torque,were optimized..Electromagnetic verification confirms this design provides effective impedance shielding,offering a solution to mitigate wake-field-induced instabilities at flange connections in high-energy accelerators.关键词
电子加速器/高重频/尾场/束流耦合阻抗/屏蔽结构Key words
electron accelerator/high repetition rate/wakefield/beam coupling impedance/RF shielding分类
能源科技引用本文复制引用
赵峰,朱潇潇,尉伟,常仁超,张浩,林涵文..一种RF屏蔽型CF法兰-密封圈结构设计[J].强激光与粒子束,2025,37(9):60-68,9.基金项目
深圳市科技计划项目(JCYJ20220530140807017) （JCYJ20220530140807017）
