Accurate Gyrotron Performance Prediction Based on Full 3-D Magnetic Field and Electron Beam Information Altered by Nonideal Factors

We improved the accuracy of gyrotron performance analysis using particle-in-cell (PIC) code. To accurately predict the performance of a device under development, an electron beam (e-beam) that has information that best represents realistic e-beam information should be used for a cavity simulation, and an investigation of factors that affect the e-beam information is necessary at the design stage. Thus, we conducted an intensive analysis of the association between the e-beam information changed by nonideal factors and the performance variation of the gyrotron cavity. The altered e-beam information was obtained using a fully 3-D commercial code (Computer Simulation Technology (CST) Studios), with consideration of manufacturing imperfections and misalignment. The acquired e-beam information was then directly imported and used for gyrotron cavity simulations with the CST PIC code. This allowed us to investigate the gyrotron performance degradation caused by the nonideal e-beam information. Additionally, we validated the CST results using our in-house gyrotron code (UNIST Gyrotron Design Tool, UGDT). Finally, the simulation results were compared with previously published experimental data.