Free boundary ideal magnetohydrodynamic stability of three-dimensional stellarators
The 3-D ideal MHD stability code TERPSICHORE is used to investigate the global external stability properties of the ATF device and the Wendelstein 7-X device. The stability of 3-D ATF equilibria with zero net toroidal plasma current and bell shaped pressure profiles shows that: (a) external modes alter the internal stability properties; (b) the coupling between the main toroidal Fourier components of the mode and their sidebands is destabilising; (c) the stabilising outward shift of the magnetic axis is confirmed; (d) the quadrupole field deteriorates stability by annihilating the vacuum magnetic well, and (e) global stability is insensitive to pressure profile effects. The ideal MHD stability of a sequence of configurations with zero net toroidal current, that varies from a conventional L = 2 stellarator to the proposed Wendelstein 7-X device, shows that the mode structures are essentially internal and that this proposed configuration is stable to global modes at beta = 4.5% with a safe margin.
Bibliographic Reference: Article: 13th International Conference on Plasma Physics and Controlled Nuclear Fusion Research, Vol. 2 (1991) pp. 793-807
Record Number: 199111482 / Last updated on: 1994-12-02
Original language: en
Available languages: en