双窗、可调耦合度、连续波型超导腔高功率输入耦合器的研究

当前，射频超导技术广泛应用于高能加速器上。如ERL光源、ADS、ILC、FEL等，均采用了超导加速腔。输入耦合器是超导腔系统的关键部件之一，其承担着功率传输、真空隔离和温度过渡等多重功能，往往影响到超导腔的性能及运行稳定性，因此其研究一直是加速器射频超导领域的热点之一。目前，单窗连续波型和双窗脉冲型输入耦合器的研究日趋成熟，但双窗、连续波型输入耦合器的研究水平还有待提高。随着加速梯度和加速能量的不断提高，为了更好地保证超导腔的高洁净度和高真空安全性，对高平均功率水平的双窗型耦合器的需求非常迫切；同时，为了确保不同流强下的高效率运行，希望耦合度能在线可调。本项目拟开展双窗、可调耦合度、连续波型输入耦合器的研究，解决高频性能优化、波纹管发热、内导体冷却、真空密封、耦合度调节、强流下耦合器与束腔相互影响等关键问题。本研究将提高超导腔输入耦合器的研究水平，为我国未来高能超导加速器的建造增加技术储备

Nowadays, superconducting radio frequency (SRF) technology has been widely applied in high energy accelerators, such as Energy Recovery Linac (ERL), Accelerator Driven subcritical System (ADS), International Linear Collider (ILC), Free Electron Laser (FEL) and so on. High power input coupler, as key component of superconducting system,is a complex device that must perform several tasks: RF power transferring, vacuum barrier and room-cryogenic temperature bridging. The multi-function makes it often affecting the superconducting cavity (SCC) performance. Therefore, the study on high power input coupler has always been a hot research topic in SRF field. Now, the research on the single-window,continuous-wave (CW) and the double-window,pulse-wave input coupler is more and more mature; however, the research level for double-window,CW input coupler needs to be promoted further. With constant upgrades in accelerating gradient and energy, we are crying out for double-window coupler with higher average RF power transferring capability to assure the high cleaness and vacuum safety. Furthermore, the adjustable coupling is desired to match different beam loading. This project focuses on double-window, variable coupling,CW input coupler study,which includes the RF performances, bellow heat, cooling, vacuum sealing, adjustable coupling, complicated interactions among the coupler and cavity with high-intensity beams. This research will improve performance of the double-window,CW high power input coupler,which will provide technical reserves for high energy superconducting accelerator in future.