EQUILIBRIUM, TRANSPORT AND STABILITY OF A PLASMA IN A TOKAMAK
At the slow diffusion time scale, the plasma is described in a Tokamak by a sequence of equilibria which are linked together by the transport phenomena and by the resistive diffusion of the poloidal magnetic flux. The 2D axisymmetric equilibrium equations are given and coupled with the set of 1D diffusion equations obtained by averaging the transport equations over the flux lines. Finite elements and finite differences are used respectively for solving these two systems. The topics of main interest are interchange and tearing instabilities, which produce respectively convective motion and magnetic islands. Non linear branches of solutions for these instabilities are considered as a bifurcation problem. Numerical simulations have been obtained for two simplified 2D models, using generally a finite element code, and sometimes spectral codes, resulting in branches of stationary solutions. For a reduced system of equations, successive bifurcations are found.
Bibliographic Reference: REPORT: EUR-CEA-FC-1375 EN (1989) AVAILABLE FROM CEA
Record Number: 1989128019400 / Last updated on: 1990-11-09
Available languages: en