A nonlinear gyrokinetic simulation, which incorporates both the reversed shear Alfvén eigenmode (RSAE) and the ion temperature gradient (ITG) turbulence, has been performed using the electromagnetic gyrokinetic Particle-In-Cell (PIC) code GEM. Strong nonlinear wave coupling and energy transfer between RSAE and ITG turbulence have been observed. Specific analyses show that the n = 4 Alfvén eigenmode primarily interacts with the ITG harmonics with long wavelength (). It is found that a background ITG turbulence can suppress the saturation level of RSAE and change the energetic particle transport. The frequency up-shift of RSAE and the frequency modulation on ITG components by RSAE are also observed. The impacts of the initial condition on the RSAE-ITG turbulence simulation are also discussed.
This paper investigates the complex interactions between ion temperature gradient (ITG) turbulence and reversed shear Alfvén eigenmodes (RSAEs) using gyrokinetic simulations. It reveals strong nonlinear coupling and energy transfer between these two phenomena, with the ITG turbulence suppressing RSAE saturation and affecting energetic particle transport. The study also observes frequency shifts and modulations, providing insights into the dynamic behavior of fusion plasmas.