Fourier-spectral element approximation of the ion-electron Braginskii system with application to tokamak edge plasma in divertor configuration

JOURNAL OF COMPUTATIONAL PHYSICS

卷:321

Article

Minjeaud, Sebastian^1,2  Pasquetti, Richard^1,2 

[1] Univ Nice Sophia Antipolis, Lab JA Dieudonne, UMR CNRS 7351, F-06108 Nice, France

[2] INRIA Project CASTOR, Nice, France

关键词: Magnetic confined fusion;    Edge plasma;    Braginskii closures;    High order methods;   

DOI  :  10.1016/j.jcp.2016.05.056

来源: Elsevier

【 摘 要 】

Due to the extreme conditions required to produce energy by nuclear fusion in tokamaks, simulating the plasma behavior is an important but challenging task. We focus on the edge part of the plasma, where fluid approaches are probably the best suited, and our approach relies on the Braginskii ion-electron model. Assuming that the electric field is electrostatic, this yields a set of 10 strongly coupled and non-linear conservation equations that exhibit multiscale and anisotropy features. The computational domain is a torus of complex geometrical section, that corresponds to the divertor configuration, i.e. with an X-point in the magnetic surfaces. To capture the complex physics that is involved, high order methods are used: The time-discretization is based on a Strang splitting, that combines implicit and explicit high order Runge-Kutta schemes, and the space discretization makes use of the spectral element method in the poloidal plane together with Fourier expansions in the toroidal direction. The paper thoroughly describes the algorithms that have been developed, provides some numerical validations of the key algorithms and exhibits the results of preliminary numerical experiments. In particular, we point out that the highest frequency of the system is intermediate between the ion and electron cyclotron frequencies. (C) 2016 Elsevier Inc. All rights reserved.

【 授权许可】

Free