A heating mechanism of electron plasmas by high-power microwaves in a magnetic mirror is investigated theoretically, with reference to experiments in a device named TP-M. The heating is assumed to be due to a microwave mode propagating perpendicular to the magnetic field since higher harmonic resonances, the main features of the experiments, exist. The heating mechanism can be interpreted in terms of a stochastic process, a random walk in velocity space.It is confirmed numerically that localized resonance zones of finite width exist, the electrons are effectively heated only in the resonance zones, and that the presence of a randomization process of the relative phase relation between the wave and the electron gyration is essential for the heating process. On the basis of the numerical analysis, the heating process is treated analytically. The electrons are assumed to pass the resonance zones repeatedly in the course of oscillatory motions between turning points, and the relative phase relation is assumed to be random at each passage through the resonance zone. The heating rate is calculated and found to agree with the experimental value. The causes of phase randomization, the effects of the loss cone and the observed saturation of electron temperature are also discussed.
磁镜中高功率微波对电子等离子体的加热机制，以TP-M装置中的实验为参照，进行了理论研究。加热被认为是由一种垂直于磁场传播的微波模式引起的，因为高次谐波共振是实验的主要特征。该加热机制可以解释为一种随机过程，即速度空间中的随机游走。数值上证实了有限宽度的共振区存在，电子仅在共振区内被有效加热，并且波与电子回旋运动之间相对相位的随机化过程对加热至关重要。基于数值分析，加热过程被解析地处理。假设电子在转折点之间反复穿越共振区，并且每次穿越时相对相位是随机的。计算了加热率，结果与实验值相符。此外，还讨论了相位随机化的原因、损失锥的影响以及观察到的电子温度饱和现象。