Hamada coordinates: Difference between revisions

(Created page with 'Hamada coordinates are a set of magnetic coordinates in which the equilibrium current density <math>\mathbf{j}</math> lines are straight…')
 
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In a coordinate system where <math>\mathbf{j}</math> is straight <math>\tilde{\eta}</math> is a function of <math>\psi</math> only, and therefore LHS of this equation must be zero in such a system. It therefore follows that the Jacobian of the Hamada system must satisfy  
In a coordinate system where <math>\mathbf{j}</math> is straight <math>\tilde{\eta}</math> is a function of <math>\psi</math> only, and therefore LHS of this equation must be zero in such a system. It therefore follows that the Jacobian of the Hamada system must satisfy  
:<math>
:<math>
  \sqrt{g_H}^{-1} = \langle\sqrt{g_H}^{-1}\rangle = \frac{4\pi^2}{V'}~,
  \sqrt{g_H} = \langle\sqrt{g_H}^{-1}\rangle^{-1} = \frac{V'}{4\pi^2}~,
</math>
</math>
where the last idenity follows from the [[Flux coordinates#Useful properties of the FSA|properties of the flux surface average]].
where the last idenity follows from the [[Flux coordinates#Useful properties of the FSA|properties of the flux surface average]].
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