Resistive ballooning modes in W7-AS and W7-X
This paper compares the stability behaviour of the W7-AS stellarator and a HELIAS (helical advanced stellarator) configuration with W7-X parameters with respect to ballooning modes. The results are based on the evaluation of a fourth order magnetic differential equation along closed magnetic field lines. The numerical procedure applies a variational approach which uses the Garching resistive ballooning code, GARBO. This analysis, which concerns purely growing modes, shows that the favourable stability properties of W7-X persist in the resistive regime. The destabilising effect of resistivity is largely compensated by the stabilising contribution of plasma compression. For the W7-AS, greater resistive effects were found, in a configuration that was already much more unstable.
Bibliographic Reference: Article: Nuclear Fusion, Vol. 33 (1993) No. 9, pp. 1281-1291
Record Number: 199411130 / Last updated on: 1994-11-25
Original language: en
Available languages: en