中文摘要：

为了发展大功率高效率太赫兹辐射源,对小回旋电子注激励三次谐波太赫兹电子回旋脉塞进行了研究,分析了不同参数情况下的模式竞争.研究结果表明,采用近轴小回旋电子注能够实现三次谐波单模振荡.在此基础上设计了一只0.52 THz、TE37模三次谐波回旋管,数值计算表明,该回旋管在工作磁场为6.98 T下输出功率可以达到3.7 kW.对产生近轴小回旋电子注的高磁压缩比磁控注入式电子光学系统进行的粒子模拟研究结果表明,该电子枪能够产生满足实验要求的65 kV/2.5 A,横纵速度比为1.24,引导中心半径0.35 mm的小回旋电子注,其纵向速度离散6.6%,横向速度离散6.1%.

英文摘要：

A third harmonic little-orbit gyrotron oscillator is investigated theoretically in order to develop high power and efficiency terahertz（THz） radiation sources.Mode competition with different electron-beam parameters have been investigated in a 0.52 THz third harmonic TE37 mode gyrotron oscillator,which can generate 3.7kW of RF power at resonant magnetic field 6.98T.In addition,a high magnetic compression ratio magnetron injection gun（MIG） with 65 kV/2.5 A has been developed.PIC simulation results show that the velocity ratio of electron beam is 1.24,the average beam radius in the cavity is 0.35 mm.The spread of perpendicular and parallel velocities are 6.1% and 6.6%,respectively.