根据正电子发射断层显像(PET)回旋加速器的物理要求与实际情况，确定了PET回旋高频双腔体的具体设计方案。在加速电压比较高的要求下，充分利用有限的空间，设计1/4波长线的异型覆面的竖腔结构腔体，采用短路片与移动电容板双调谐结构，满足了频率调谐要求；同时获得较高的品质因数，达到了物理设计要求的加速电压。利用Microwave Studio CST程序对腔体的Q0值、热分布、功率损耗、微调电容做了详细的分析与计算；对实际测量值与仿真计算值进行了对比，并对产生的误差进行了分析和讨论。腔体电压实际测量值达到50 kV以上，频率稳定度达到设计指标1.0×10-6/d。

According to the physical requirements and the actual situation of Positron Emission Tomography (PET) cyclotrons at Institute of Modern Physics, Chinese Academy of Sciences (IMP, CAS), a new compact RF cavity with a quarter wave resonator structure and a profiled cover was designed with high accelerated e-field gradient. Additionally, a special dual tuning structure with a short-plate and a movable capacitor plate was designed to meet the requirements of complicated tuning operation mode. The simulated results from Microwave Studio (CST) showed that the design obtained a high quality factor and reached a rated accelerated voltage. The electro-magnetic analysis was carried out, and the power loss tolerance and the thermal distribution were calculated. A prototype cavity was fabricated and measured in January, 2013, and the tested results indicated that the accelerated voltage was higher than 50 kV and the frequency stability was 10-6/d, both of them reached the original design specification. This proves that the measured results agree well with the simulated ones. All detailed simulations and measurements were analyzed and discussed.