Analyzing Vacuum Tube Operation for a Wideband Cavity Using a Circuit Simulator

Analyzing tetrode tube operation is crucial for the design and optimization of RF systems in proton/heavy ion synchrotrons, especially for high beam circulating current operations. This task presents significant challenges due to the complexity of the system. In this article, we introduce a novel approach to analyze tube operation using a circuit simulator. By modeling the entire RF system within the circuit simulator, we enable real-time simulation of the system’s behavior, which allows for accurate determination of tube operation. This method proves to be effective in multiharmonic scenarios where multiple variables need to be resolved. We detail the methods used to model the RF system of the China Spallation Neutron Source (CSNS) in the circuit simulator, which includes the wideband cavity, vacuum tube amplifier, and low-level RF (LLRF) control system. The simulation results are presented and discussed, showing reasonable agreement with experimental measurements.