Stellarator optimization

In tokamaks, a significant part of the confining magnetic field is produced by the currents flowing in the plasma itself. In contrast, the confining magnetic field of stellarators may be dominated by externally imposed magnetic fields (depending on the configuration). Since the confinement properties of toroidally confined devices depend sensitively on the magnetic field, the question arises whether this external control may be used to improve confinement properties, and thus facilitate the development of an economically attractive stellarator reactor.

Several optimization strategies have been developed and/or are being studied. ^[1]

Optimization of Neoclassical transport.^[2] See omnigeneity and quasisymmetry.
Optimization of Anomalous transport.^[3]

Optimized stellarators

W7-X - Neoclassical optimization; under construction
HSX - Quasihelical symmetry; operational
QPS - Quasipoloidal symmetry; cancelled
NCSX - Quasi-axisymmetry; cancelled

Also see: US Stellarator proof-of-principle program

References

↑ H.E. Mynick, Transport optimization in stellarators, Phys. Plasmas 13 (2006) 058102
↑ H. Wobig, The theoretical basis of a drift-optimized stellarator reactor, Plasma Phys. Control. Fusion 35 (1993) 903
↑ H.E. Mynick, N. Pomphrey, and P. Xanthopoulos, Optimizing Stellarators for Turbulent Transport, Phys. Rev. Lett. 105 (2010) 095004

[1] H.E. Mynick, Transport optimization in stellarators, Phys. Plasmas 13 (2006) 058102

[2] H. Wobig, The theoretical basis of a drift-optimized stellarator reactor, Plasma Phys. Control. Fusion 35 (1993) 903

[3] H.E. Mynick, N. Pomphrey, and P. Xanthopoulos, Optimizing Stellarators for Turbulent Transport, Phys. Rev. Lett. 105 (2010) 095004

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