设计了用于W波段三次谐波回旋管的带有iris结构的开放式谐振腔。采用低损耗圆对称模式TE₀₂工作。起振电流为2.9 A,欧姆效率67%。PIC数值模拟结果表明,TE02模式在iris谐振腔中可以实现稳定的W波段三次谐波单模振荡。当电压为45 kV、电流为4 A、横纵速度比为1.5时,可以获得25.7 kW功率输出,对应的工作效率为14.3%。

The design of an iris cavity for a W-band third harmonic gyrotron is presented. The gyrotron is designed to operate at the low loss, circular symmetric TE₀₂ mode. The minimum start current is 2.9 A and the ohmic efficiency is 67%. When the gyrotron is driven by a 45 kV, 4 A electron beam with an orbital-to-axial velocity ratio equal to 1.5, an output power of 25.7 kW at 94.8 GHz is predicted from PIC simulation, corresponding to an efficiency of 14.3%.