Spheromak Tilting Instability in Cylindrical Geometry.
Abstract
The compact torus, or spheromak, approach to magnetic fusion has numerous advantages as a reactor over tokamak designs. Most important of these are relative compactness, the fact that a toroidal blanket is not necessary, and the absence of external toroidal field coils. Theoretical work by Rosenbluth and Bussac has shown that a spheromak plasma in a tight fitting spheroidal shell is unstable to a magnetohydrodynamic mode which they call the internal tilting mode if the boundary is slightly elongated, i.e. prolate. Recently, a spheromak-type configuration has been formed at the University of Maryland by a combination of Z-pinch and theta pinch technologies. Although the spherical wall equilibrium of Ref. 2 describes this device in a qualitative fashion, a more appropriate theoretical model for the Maryland device is an equilibrium with cylindrical conducting walls and endplates. In addition, we feel that it is of value to show that the tilting instability is not specific to systems with conducting walls that are almost spherical. Detailed comparison of the model with the experimental device and the observed tilting instability with the theory has been presented elsewhere. In this paper we describe in more detail two of the theoretical approaches used and their justification.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 25, 1980
- Accession Number
- ADA090034
Entities
People
- Edward Ott
- John M. Finn
- Wallace M. Manheimer
Organizations
- United States Naval Research Laboratory