Simulation Of Resistive Tearing Mode In Tokamak

As energy crisis is severe nowadays, controlled fusion energy becomes the most important alternative since it's largely stored and clean. Magnetic confinement fusion devices such as tokamak are seen as the most prominent approach. In tokamak,tearing mode (neoclassical tearing mode) is one of the most dangerous problems as it can change the topology of the magnetic field, break the particle frozen state, and impact the confinement of particle and energy, thus leading to the disruption of the sustainable maintenance of the device. Tearing mode itself is deeply influenced by the comprehensive interactions among micro-turbulence, neoclassical transport, macro MHD instabilities, and energetic particle physics. Since it is a multi-scale process in time and space, it is hard to carry out the analytic calculation, therefore the integrated simulation based on first principles becomes a useful tool. For this final goal, we've done some primary research such as simulations of tearing mode and static magnetic island.First of all, we've recalled the gyrokinetic theory and briefly introduced the Gyrokinetic Toroidal Code (GTC) program. In the electromagnetic theory model of GTC,tearing mode is removed. We've retained the physics mechanism for tearing mode by adopting the electron parallel force balance equation, based on which a new electromagnetic model for tearing mode simulation is established and a new module capable of dealing with tearing mode simulation is programmed. Then, by using the newly developed massive parallel gyrokinetic particle-in-cell (PIC) platform --- VirtEx,and choosing the newly established model and implemented module, we've carried out a series of simulations of tearing mode. The linear simulation shows a satisfactory agreement with the theoretical calculation, which verifies the correctness of the model and module for tearing mode simulation.In simulations of global mode like kink mode and tearing mode, Lalpacian Equation in field-line coordinate suffers the singularity problem when the calculation domain is expanded to the central area. The current solution in GTC is extrapolating the solution linearly to the center. In order to solving this problem and problems across and beyond the last closed flux surface the scrape-off-layer (SOL) in particular, we've implemented another finite element (FE) solver in GTC. By testing function verification and realistic physics case simulation, the accuracy of the FEM solver is verified.Moreover, we've also started the research on the simulation of the static island's nonlinear impact on electrostatic drift wave instabilities. We've employed the drift kinetic model to treat electron. So far, we've successfully verified the implementation of the static island and obtained the flattened particle density profile within the island.The simulation of ITG mode using DKE model is still under research.