Formulations and verification of gyrokinetic simulation of kinetic-MHD processes in toroidal plasmas (2109.08873v2)

Abstract: A set of electromagnetic formulations with gyrokinetic ions and drift kinetic electrons for global gyrokinetic simulations has been formulated and verified in the framework of Gyrokinetic Toroidal Code (GTC), which is particularly suitable for the low-frequency electromagnetic modes including drift waves, Alv\'{e}n Eigenmodes and MHD modes. This gyrokinetic simulation model can reduce to the ideal MHD model in the long wavelength limit, and recover the well-known MHD dispersion relation. Especially, the magnetic compression perturbation and the equilibrium current are carefully treated in this model. Furthermore, the detailed implementation of the equations in Boozer coordinate system is provided. The internal kink mode simulations in DIII-D and ITER tokamaks using this model have been successfully bench-marked with other kinetic and MHD codes. The physical model has also been used to generate a database to train the machine learning surrogate model of GTC.