تحليل نظري و شبيه‌سازي عددي توصيف جنبشي-چرخشي پلاسما در توكامك‌ها: حالت‌هاي خطي، غيرخطي و سراسري، موضعي

Theoretical Analysis an‎d Numerical Simulation of Gyro-Kinetic description of plasma in tokamaks: Linear, Nonlinear an‎d Global, Local Modes

plasma , tokamak , gyrokinetic description , ion temperature gradient mode , numerical simulation , GENE code , flux tube approximation , linear an‎d nonlinear analysis

Theoretical Analysis an‎d Numerical Simulation of Gyro-Kinetic description of plasma in tokamaks: Linear, Nonlinear an‎d Global, Local Modes

مهندسي هسته‌اي

In this study, a theoretical analysis an‎d numerical simulation of the gyrokinetic description of plasma in tokamaks is presented, with a focus on ion temperature gradient (ITG) modes. The primary motivation of the research is to investigate the role of microinstabilities an‎d the associated mechanisms of anomalous transport in reducing the efficiency of magnetic confinement, an‎d to provide a practical framework for application in the design an‎d optimization of national tokamak devices. In the theoretical section, the derivation of the gyrokinetic equations from the Vlasov equation, the principles of gyro-averaging, an‎d the approximations required to reduce the six-dimensional phase space to a five-dimensional form suitable for numerical computation are thoroughly explained. Additionally, topics such as flux tube modeling, boundary conditions, an‎d the effects of magnetic field geometry are reviewed. On the numerical side, implementation an‎d parameter tuning were carried out using the well-established GENE code. A set of simulation cases were designed an‎d executed in both local an‎d global frameworks, an‎d in both linear an‎d nonlinear regimes, to assess the sensitivity of mode behavior to variations in profiles an‎d geometry. Discretization methods, choice of spatial an‎d velocity grids, parallelization settings, an‎d procedures for extracting diagnostic quantities (such as growth rates, flux spectra, an‎d spectral analysis) were systematically documented to ensure the reproducibility of results. From an applied perspective, this work serves two main purposes: first, it provides a step-by-step guide for deriving an‎d implementing gyrokinetic equations in numerical environments; second, it offers a curated experimental set of simulations an‎d parameter files that can serve as a research infrastructure for future studies an‎d for use in the analysis of domestic operational tokamaks. In doing so, the thesis bridges fundamental theory an‎d practical simulations, laying the groundwork for future research aimed at reducing anomalous transport an‎d improving control strategies in fusion reactors.

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