The formation of magnetic islands as a result of plasma pressure in three-dimensional equilibria is investigated by a boundary-layer analysis. Away from a rational surface ("exterior region"), the plasma current is calculated exactly from the equilibrium equations. The singularity in the current thus calculated is resolved by analysis of the equilibrium equations in the vicinity of the rational surface ("inner region"). The Δ′ parameter of tearing mode theory is used to match the inner and outer regions. The island width is found to depend on the resistive interchange criterion, as seen in the work of Glasser, Greene, and Johnson [Phys. Fluids 18,875 (1975)]. Estimates of island sizes for different stellarator experiments are given.
All Science Journal Classification (ASJC) codes
- Computational Mechanics
- Condensed Matter Physics
- Mechanics of Materials
- General Physics and Astronomy
- Fluid Flow and Transfer Processes