Portal de Periódicos da CAPES

A numerical study of MHD equilibrium and stability of the spheromak

1980; IOP Publishing; Volume: 20; Issue: 5 Linguagem: Inglês

10.1088/0029-5515/20/5/006

1741-4326

M. Okabayashi, A.M.M. Todd,

Plasma Diagnostics and Applications

The MHD-stability of spheromak-type equilibria from the classical spheromak configuration to the diffuse-pinch limit is analysed numerically. It is found that oblate configurations of ellipticity 0.5 have optimum stability properties with regard to internal MHD-modes and can be stabilized up to an engineering β of 15% (defined with respect to the applied external field strength for equilibrium). Stability to global modes requires that a conducting shell surround the plasma. The location of the shell is dependent on geometry and current profile, but realistic configurations that are stable to all ideal MHD-modes have been found with the shell located at about 1.2 of the minor radius.