Ultrahigh accelerating gradient and quality factor of CEPC 650 MHz superconducting radio-frequency cavity

作     者：Peng Sha Wei-Min Pan Song Jin Ji-Yuan Zhai Zheng-Hui Mi Bai-Qi Liu Chao Dong Fei-Si He Rui Ge Liang-Rui Sun Shi-Ao Zheng Ling-Xi Ye Peng Sha;Wei-Min Pan;Song Jin;Ji-Yuan Zhai;Zheng-Hui Mi;Bai-Qi Liu;Chao Dong;Fei-Si He;Rui Ge;Liang-Rui Sun;Shi-Ao Zheng;Ling-Xi Ye

作者机构：Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Key Laboratory of Particle Acceleration Physics and TechnologyChinese Academy of SciencesBeijing 100049China Center for Superconducting RF and CryogenicsInstitute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of SciencesBeijing 100049China 

出 版 物：《Nuclear Science and Techniques》 (核技术（英文）)

年 卷 期：2022年第33卷第10期

页      面：33-40页

核心收录：

学科分类：07[理学] 08[工学] 082701[工学-核能科学与工程] 0827[工学-核科学与技术] 070202[理学-粒子物理与原子核物理] 0702[理学-物理学] 

基　　金：supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB25000000) the National Natural Science Foundation of China(No.12075270) the Platform of Advanced Photon Source Technology R&D 

主　　题：SRF cavity Accelerating gradient Quality factor Electropolishing Vertical test 

摘      要：Two 650 MHz single-cell superconducting radio-frequency(SRF)cavities used for the Circular Electron Positron Collider(CEPC)were studied to achieve a high accelerating gradient(E_(acc))and high intrinsic quality factor(Q_(0)).The 650 MHz single-cell cavities were subjected to a combination of buffered chemical polishing(BCP)and electropolishing(EP),and their E_(acc) exceeded40 MV/*** a high E_(acc) may result from the cold EP with more uniform *** is easy,cheap,and rough,whereas EP is complicated,expensive,and precise Therefore,the combination of BCP and EP investigated in this study is suitable for surface treatments of mass SRF *** temperature(mid-T)furnace baking was also conducted,which demonstrated an ultrahigh Q_(0) of 8×10^(10) at 22 MV/m for both cavities,and an extremely low BCS resistance(R_(BCS))of~1.0 nΩwas achieved a2.0 K.