兆瓦级回旋管电子注性能及注-波互作用模拟分析OA

[Background]The gyrotron is a relativistic nonlinear device capable of generating high-power electromagnetic radiation in the millimeter-wave and terahertz frequency ranges.In most operating magnetically confined thermonuclear fusion reactors(for electron cyclotron heating and current drive,ECH&CD),high-power gyrotrons serve as the core microwave source devices for their electron cyclotron wave heating and current drive systems.For high-power gyrotrons,the high-frequency cavity must operate in a high-order whispering gallery mode to meet the power capacity requirements.However,high-order mode operation conversely introduces severe mode competition.Electron beam performance is a major factor affecting the mode competition,further limiting their efficient and stable operation,particularly in long-pulse or continuous-wave regimes.Therefore,it is essential to investigate the impact of megawatt-level gyrotron electron beam performance on beam-wave interaction.[Purpose]The study focuses on a self-developed megawatt-level 170 GHz gyrotron operating at TE25,10 mode,analyzing the structural parameter variations of the high-frequency cavity,the start-oscillation current,and the mode competition in single/dual-anode electron beam modulation.[Method]This paper comprehensively considers electron beam performance(velocity spread,beam thickness,space charge effects,oscillation startup process,single/dual-anode configuration)and establishes a sophisticated time-domain,multi-mode,multi-frequency self-consistent nonlinear beam-wave interaction model.[Results]Under operating conditions of 80 kV beam voltage,40 A beam current,6.72 T magnetic field,and a velocity ratio of 1.3,the output power reaches 1.35 MW with an interaction efficiency of 42.2%.[Conclusion]Numerical simulations demonstrate that the dual-anode modulation method significantly suppresses mode competition.The successful demonstration of this device establishes a foundation for further studies on higher power and higher-frequency gyrotron.