Toroidal field effects on dipole equilibrium and stability at finite plasma pressure
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, 167 Albany Street, NW16, Cambridge, Massachusetts 02139 (United States)
The influence of a toroidal magnetic field on the equilibrium and stability of a plasma confined by the magnetic field of a point dipole is considered, since it may be necessary to introduce a toroidal magnetic field to smooth electron heating or other asymmetries in the toroidal direction that can lead to toroidal electric fields and a loss of confinement due to radial ExB drift. To begin, a toriodal magnetic field is shown to restore confinement by reducing electron heating departures from axisymmetry. Then the Grad-Shafranov equation for a point dipole in the presence of a toroidal field is solved to explicitly demonstrate that an equilibrium exists. Finally, it is shown that a toroidal magnetic field destabilizes the otherwise stable point dipole ballooning modes at high plasma pressure. Consequently, if a toroidal magnetic field is necessary to remove toroidal heating asymmetries in a dipole equilibrium, the heating may have to be performed transiently or at lower plasma pressures. (c) 2000 American Institute of Physics.
- OSTI ID:
- 20216034
- Journal Information:
- Physics of Plasmas, Vol. 7, Issue 5; Other Information: PBD: May 2000; ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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