Nonlinear Effects of High Power Plug/Barrier Electron Cyclotron Resonance Heating on Propagation and Radiation of Cyclotron Waves

Nonlinear electromagnetic waves generated due to the injection of high-power electromagnetic waves relating to an electron cyclotron resonance (ECR) are investigated in the GAMMA10 tandem-mirror fusion device and the Q_T-Upgrade laboratory device. In the GAMMA10 device, an electrostatic wave in the ion-cyclotron range of frequencies is observed around a west barrier region. During the barrier and plug electron cyclotron resonance heating (ECH), the nonlinear electromagnetic waves with the interval of the frequency corresponding to the electrostatic fluctuation are radiated from the plug region. In the Q_T-Upgrade laboratory device, on the other hand, the injected microwave nonlinearly interacts with an electrostatic drift-wave instability. These results in the GAMMA10 and the Q_T-Upgrade devices indicate the radiation of the electromagnetic waves originating from the parametric instability.