中国散裂中子源二期648 MHz超导腔调谐器设计

Design of 648 MHz superconducting cavity tuner forChina Spallation Neutron Source phase II

中国散裂中子源二期升级采用超导腔技术方案,其中在165~300 MeV能量段采用648 MHz 6-cell超导腔模组,每个模组中集成3只6-cell超导腔。超导腔工作在脉冲模式,为了保证超导腔2 K下的频率满足运行要求,每只超导腔需要一套低温调谐器对其频率进行精确调节控制。针对648 MHz 6-cell超导腔的结构和运行特点进行了低温调谐器的设计,采用快慢组合机构补偿超导腔的频率偏移,对调谐器的基本性能和超导腔脉冲模式运行下的动态洛伦兹失谐进行了分析。

The China Spallation Neutron Source phase II(CNSS-II)is upgraded with superconducting cavitytechnology,which uses 648 MHz 6-cell superconducting cavity module in the energy range of 165−300 MeV.Three6-cell superconducting cavities are integrated in each module.The superconducting cavity works in pulse mode.Toensure that the frequency of the superconducting cavity meets the operation requirements at 2 K,each superconductingcavity needs a set of low-temperature tuner to precisely adjust and control its frequency.According to the structure andoperation characteristics of the 648 MHz 6-cell superconducting cavity,a low-temperature tuner is designed.Thefrequency offset of the superconducting cavity is compensated by a fast-slow combination mechanism.The basicperformance of the tuner and the dynamic Lorentz detuning of the superconducting cavity in pulse mode are analyzed.