Based on the analysis of electron–wave interaction, we study the possibility of developing a gyrotron that is able to provide a megawatt output power in quasi-continuous (long-pulse) oscillations at both first and second gyrofrequency harmonics. For selective excitation at the second cyclotron harmonic when the operating current is significantly higher than its starting value, we propose to lock the gyrotron by a weak (several percent power) monochromatic incoming signal which suppresses spurious oscillations at the fundamental cyclotron resonance in the gyrotron start-up process. Simulations of a two-frequency gyrotron with an output power of 1 MW at the first cyclotron harmonic (19 GHz) and 0.8 MW at the second one (38 GHz) based on a nonstationary self-consistent system of equations are presented. Such a source of radiation is of interest for plasma-heating systems in spherical tokamaks.

基于对电子波相互作用的分析，我们研究了开发一种回旋加速器的可能性，该回旋加速器能够在一次和第二次回旋频率谐波下的准连续（长脉冲）振荡中提供兆瓦的输出功率。为了在工作电流明显高于其起始值时在第二回旋加速器谐波处进行选择性激励，我们建议通过弱的（几个功率百分比）单色输入信号来锁定回旋加速器，该信号会抑制回旋加速器启动时基本回旋加速器谐振处的杂散振荡程序。提出了一种基于非平稳自洽方程组的双频回旋加速器的仿真，该回旋加速器在第一回旋加速器谐波（19 GHz）处输出功率为1 MW，在第二回旋加速器谐波（38 GHz）处输出功率为0.8 MW。