CSNS/RCS环射频腔用铁氧体环测试系统研制

Development of ferrite ring test system for ferrite-loaded RF cavities of CSNS/RCS

为测试环射频铁氧体加载同轴谐振腔中铁氧体环的性能和批量筛选铁氧体环,研制了铁氧体双环测量系统。与国内外同类设备相比,该系统采用了扫频测量的闭环控制,可以模拟射频腔的运行工况、实现对铁氧体环性能的动态测量。扫频范围测量结果表明：该测试系统满足在0~3 000 A偏流调谐范围内的1.02~2.44 MHz频率覆盖要求,固定频率点的高功率测量结果和材料性能参数与日本J-PARC测量数据吻合。

A two-ring ferrite test system for ferrite-loaded cavities of rapid cycling synchrotron（RCS） of China spallation neutron source（CSNS） has been developed.The measurement of ferrite ring provides very important information for designing the cavities and the whole RF system.Even more,all the ferrite rings used in the RCS will be sorted based on the measurements with the test system.The cavity structure in the test system ensures the measurement reliability and repeatability with good field uniformity.A control system including LLRF control,bias current control and data acquisition has also been developed for increasing the efficiency of the test system,and it is also necessary for measurements in the frequency-sweeping mode.The preliminary cold-mode test and high-power test results in the static state are presented.