A unified approach to description of the fast and slow resistive wall modes in tokamaks

作者：Pustovitov V D^*

来源：Plasma Physics Reports, 2012, 38(9): 697-707.

DOI：10.1134/S1063780X1209005X

The formulation of the boundary conditions is considered in the problem of the resistive wall mode (RWM) stability in tokamaks. The mode-wall interaction, usually modeled in the thin-wall approximation, is described here with account of the finite thickness of the wall and skin effect. It allows one to step beyond the standard restrictions into the area of faster RWMs than the usual "slow" RWMs near the stability threshold. The analysis is carried out with the energy balance equations incorporating the dissipation in the wall. The approach is equally applicable to the modes of any kind and allows natural matching of the exterior problem with the models for the inner region. For example, it allows one to connect the outer task to the classical energy principle for the inner area. It is shown how to calculate the RWM growth rates within this model. A general algorithm with equations applicable to arbitrary toroidal systems and its full realization in the conventional cylindrical model are described. In the latter case, it is shown that the growth rate of the "fast" RWMs essentially differs from the estimates of the standard theory of slow RWMs. The analysis proves that the RWM theory has to be complemented by the additional block of calculations for more correct formulation of the boundary conditions on the inner side of the wall than that in the theory with an ideal or thin resistive wall.

• 出版日期2012-9