Kinetic modeling of 3D equilibria in a tokamak

Joint Varenna-Lausanne International Workshop on the Theory of Fusion Plasmas 2016

Albert, C.G.^1 ; Heyn, M.F.^1 ; Kasilov, S.V.^1,2 ; Kernbichler, W.^1 ; Martitsch, A.F.^1 ; Runov, A.M.^3

Fusion at ÖAW, Institut für Theoretische Physik-Computational Physics, Technische Universität Graz, Petersgasse 16, Graz

A-8010, Austria^1

Institute of Plasma Physics, National Science Center, Kharkov Institute of Physics and Technology, Akademicheskaya Str. 1, Kharkov

61108, Ukraine^2

Max-Planck-Institut für Plasmaphysik, Wendelsteinstraße 1, Greifswald

17491, Germany^3

关键词: Edgelocalized modes;    External perturbations;    Finite element solver;    Geometrical integrator;    Magnetic surfaces;    Magnetic topologies;    Nonlinear kinetics;    Self-consistent solution;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/775/1/012001/pdf
DOI  :  10.1088/1742-6596/775/1/012001

来源: IOP

【 摘 要 】

External resonant magnetic perturbations (RMPs) can modify the magnetic topology in a tokamak. In this case the magnetic field cannot generally be described by ideal MHD equilibrium equations in the vicinity of resonant magnetic surfaces where parallel and perpendicular relaxation timescales are comparable. Usually, resistive MHD models are used to describe these regions. In the present work, a kinetic model is used for this purpose. Within this model, plasma response, current and charge density are computed with help of a Monte Carlo method, where guiding center orbit equations are solved using a semianalytical geometrical integrator. Besides its higher efficiency in comparison to usual integrators this method is not sensitive to noise in field quantities. The computed charges and currents are used to calculate the electromagnetic field with help of a finite element solver. A preconditioned iterative scheme is applied to search for a self-consistent solution. The discussed method is aimed at the nonlinear kinetic description of RMPs in experiments on Edge Localized Mode (ELM) mitigation by external perturbation coil systems without simplification of the device geometry.