Studies of an LL-type 500 MHz 5-cell superconducting cavity at SINAP  

作　　者：侯洪涛 马震宇 毛冬青 封自强 罗琛 是晶 王岩 李正 徐凯 赵玉彬 郑湘 赵申杰 张志刚 刘建飞 

机构地区：[1]Shanghai Institute of Applied Physics, Chinese Academy of Sciences [2]Shanghai Key Laboratory of Cryogenics & Superconducting RF Technology [3]University of Chinese Academy of Sciences

出　　处：《Chinese Physics C》2015年第4期67-72,共6页中国物理C（英文版）

基　　金：Supported by National Natural Science Foundation of China(11175237)

摘　　要：A low loss- （LL） type 500 MHz 5-cell superconducting niobium prototype cavity with a large beam aperture has been developed successfully including the optimization, the deep drawing and electron beam welding, the surface treatment and the vertical testing. The performance of the fundamental mode was optimized and the higher order modes were damped by adopting an enlarged beam pipe for propagation. Surface preparation or treatment including mechanical polishing, buffered chemical polishing and high pressure rinsing with ultra-pure water and so on was carried out carefully to ensure a perfect inner surface condition. The vertical testing results show that the accelerating voltage higher than 7.5 MV was obtained while the quality factor was better than 1× 109 at 4.2 K. No obvious multipacting or field emission was found during the test. However, a quench happened while increasing the field a little higher than 7.5 MV that at present limited the cavity performance.A low loss- （LL） type 500 MHz 5-cell superconducting niobium prototype cavity with a large beam aperture has been developed successfully including the optimization, the deep drawing and electron beam welding, the surface treatment and the vertical testing. The performance of the fundamental mode was optimized and the higher order modes were damped by adopting an enlarged beam pipe for propagation. Surface preparation or treatment including mechanical polishing, buffered chemical polishing and high pressure rinsing with ultra-pure water and so on was carried out carefully to ensure a perfect inner surface condition. The vertical testing results show that the accelerating voltage higher than 7.5 MV was obtained while the quality factor was better than 1× 109 at 4.2 K. No obvious multipacting or field emission was found during the test. However, a quench happened while increasing the field a little higher than 7.5 MV that at present limited the cavity performance.

关 键 词：superconducting niobium cavity low loss MULTICELL fabrication optimization vertical test 

分 类 号：TL53[核科学技术—核技术及应用]