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Effective plasma radius: Difference between revisions
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:<math>\rho_{\rm eff} = \sqrt{\psi_N}</math> | :<math>\rho_{\rm eff} = \sqrt{\psi_N}</math> | ||
where ''ψ<sub>N</sub>'' is the normalized poloidal flux, such that it is | where ''ψ<sub>N</sub>'' is the normalized poloidal flux, such that it is 0 on the magnetic axis and 1 at the Last Closed Flux Surface (LCFS). | ||
Other definitions can be based on the volume ''V(ψ)'' enclosed in a flux surface, or the surface area ''S(ψ)'' of a flux surface. | Other definitions can be based on the volume ''V(ψ)'' enclosed in a flux surface, or the surface area ''S(ψ)'' of a flux surface. | ||
An effective radius can also be defined for magnetic configurations with magnetic islands, although this requires | An effective radius can also be defined for magnetic configurations with magnetic islands, although this requires applying some special treatment for points inside the islands. It may be argued that assigning an effective radius to spatial points inside a magnetic island is not very useful, since such points are topologically disconnected from the main plasma volume. Similarly, the definition of an effective radius in ergodic magnetic zones is ambiguous, since the concept of flux surface has no meaning inside an ergodic zone. | ||
<ref>[http://dx.doi.org/10.1016/j.jcp.2008.02.026 B. Seiwald et al, ''Optimization of energy confinement in the 1/ν regime for stellarators'', Journal of Computational Physics '''227''', 12 (2008) 6165-6183]</ref> | <ref>[http://dx.doi.org/10.1016/j.jcp.2008.02.026 B. Seiwald et al, ''Optimization of energy confinement in the 1/ν regime for stellarators'', Journal of Computational Physics '''227''', 12 (2008) 6165-6183]</ref> | ||
== References == | == References == | ||
<references /> | <references /> | ||