Design and analysis of positron emission tomography cyclotron RF cavity

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.