Stellarator symmetry: Difference between revisions

no edit summary
mNo edit summary
No edit summary
Line 1: Line 1:
Stellarator symmetry is a property of typical [[Stellarator|stellarator]] magnetic configurations.
Stellarator symmetry is a property of typical [[Stellarator|stellarator]] magnetic configurations.
It is important be aware that it is an ''imposed'' (artificial) symmetry,
reflecting the symmetry of the design of the external magnetic field coils generating the configuration, and
not an ''inherent'' (natural) symmetry of stellarator plasmas.
<ref>[http://dx.doi.org/10.1016/S0167-2789(97)00216-9 R.L. Dewar, S.R. Hudson, ''Stellarator symmetry'', Physica D, '''112''' (1998) 275]</ref>
In a [[Toroidal coordinates|cylindrical coordinate system]], it is expressed as follows for a scalar field:
In a [[Toroidal coordinates|cylindrical coordinate system]], it is expressed as follows for a scalar field:


Line 8: Line 13:
:<math>\left ( B_R, B_\phi, B_Z \right )_{(R,\phi,Z)} = \left ( -B_R, B_\phi, B_Z \right )_{(R,-\phi,-Z)}</math>
:<math>\left ( B_R, B_\phi, B_Z \right )_{(R,\phi,Z)} = \left ( -B_R, B_\phi, B_Z \right )_{(R,-\phi,-Z)}</math>


With ''N''-fold rotation symmetry around the ''Z'' axis, there are ''2N'' such planes. <ref>[http://dx.doi.org/10.1016/S0167-2789(97)00216-9 R.L. Dewar, S.R. Hudson, ''Stellarator symmetry'', Physica D, '''112''' (1998) 275]</ref>
With ''N''-fold rotation symmetry around the ''Z'' axis, there are ''2N'' such planes.  


== References ==
== References ==
<references/>
<references/>