A stellarator is a magnetic confinement device. The rotational transform is predominantly generated by external coils - as opposed to a tokamak, in which the poloidal field is generated by plasma currents. Hybrid concepts (including the concepts known as quasi-axisymmetry and quasi-omnigeneity) employ both external coils and self-generated (bootstrap) currents (e.g. NCSX).
Classification of stellarators
Somewhat arbitrarily, stellarators may be classified according to the type of magnetic configuration.
- Torsatron / Heliotron: the rotational transform is produced by an external helical coil surrounding the plasma.
- Heliac: a stellarator with a toroidally helical magnetic axis.
- Helias: advanced stellarator with modular coils.
- ATF (Oak Ridge, TN, USA)
- CHS (Japan)
- H-1NF (Canberra, Australia)
- NCSX (Princeton, NJ, USA) - cancelled before construction was completed
- W7-AS (Garching, Germany, 1988-2002)
- CAT/CTH (Auburn, USA)
- Heliotron-J (Kyoto, Japan)
- HSX (Madison, WI, USA)
- LHD (Toki, Japan)
- SCR-1 (Cartago, Costa Rica)
- TJ-II (Madrid, Spain)
- TJ-K (Stuttgart, Germany)
- TU Heliac (Tohoku Univ., Sendai, Japan)
- UST-1 (Spain) - tabletop experiment
- WEGA (Greifswald, Germany)
- Wendelstein 7-x (W7-X) (Greifswald, Germany)
- QPS (in design phase, TN, USA)
- STELL (in design phase, University of Lorraine, France, in collaboration with IPP Greifswald)
- Stellarator reactor
- Stellarator optimization
- International Stellarator and Heliotron Workshop
- Coordinated Working Group Meeting
- Stellarator symmetry
- Stellarator News
- ARIES Project (conceptual design of a compact stellarator)
- Spherical Stellarator design study