Speaker
Description
See full abstract here
http://ocs.ciemat.es/EPS2019ABS/pdf/P4.1074.pdf
Full-wave analysis including kinetic effects of plasmas has been extensively employed in studying wave heating and current drive in tokamak plasmas. Most of previous kinetic analyses of wave propagation and absorption in an inhomogeneous plasma are based the wave number.
The dielectric tensor in a hot plasma has been usually expressed as a function of wave number. In the full-wave numerical analysis using the finite element method (FEM) or the finite difference method (FDM), however, the wave number is not available a priori. In order to describe the response of plasma without wave number, it is appropriate to use an integral form of the dielectric tensor derived by integrating along an unperturbed particle orbit. Maxwell's equation with the integral form of dielectric tensor (see formula at http://ocs.ciemat.es/EPS2019ABS/pdf/P4.1074.pdf)
can be numerically solved as a boundary-value problem by FEM. Numerical analysis with FEM may have higher performance with parallel processing owing to sparse coefficient matrix. Though the integration is localized in an element in usual FEM for differential equations, coupling between different elements occurs in FEM for integro-differential equations. In a magnetized plasma, the guiding center motion along an inhomogeneous magnetic field and the cyclotron motion perpendicular to the magnetic field can be separately taken into account in deriving the dielectric tensor as an integral operator. 1D full-wave analysis using the integral form of dielectric tensor was applied to ion cyclotron (IC) heating in the presence of energetic ions and the O-X-B mode conversion of electron cyclotron (EC) waves. In this presentation, 2D full-wave analysis with the integral form of dielectric tensor is provided. The first application is the analysis of 2D mode structure of the O-X-B mode conversion on the horizontal plane of tokamak. The tunneling of the wave over the evanescent layer between O-mode and X-mode
cutoffs is described without any assumptions, and the results are compared with the convention ray tracing analysis with some adjustments. The second application is the analysis of 2D mode structure on the poloidal plane of tokamak. The inhomogeneity of the magnetic field along the field line is taken into account, and the magnetic mirror motion of charge particles is taken into account. Examples of the O-X-B mode conversion of EC waves, Landau damping of lower-hybrid (LH) waves, and IC higher harmonic heating will be demonstrated.
