Vlasov-MHD and Particle-MHD Simulations of the Toroidal Alfven Eigenmode

"Two simulation codes, Vlasov-MHD code and particle-MHD code, are developed to elucidate nonlinear behavior of hybrid kinetic-MHD modes and energetic particles. Simulations of the toroidal Alfven eigenmode (TAE mode) destabilized by energetic alpha particles are carried out. Vlasov-MHD simulation revealed that particle-trapping by a finite-amplitude wave causes the saturation. After saturation, amplitude oscillation takes place with a frequency corresponding to the bounce frequency of the alpha particles trapped by the TAE mode. Particle-MHD simulations are performed with more relevant condition to fusion plasmas, and saturation caused by particle-trapping is confirmed.