Description
When an otherwise symmetric tokamak plasma is exposed to asymmetric magnetic perturbations, the plasma separatrix ceases to exist and is replaced by a pair of invariant manifolds. The intersection of the outermost manifold with the target plate leads to the formation of magnetic footprints and, consequently, to the splitting of the peak heat flux to the target.
This contribution demonstrates the application of Melnikov’s integral method to localize the boundary of the magnetic footprint using newly introduced homoclinic coordinates. The semi-analytical approach enables the identification of generic magnetic footprint behavior in real-world tokamaks that may not be apparent in traditional field-line tracing.
The linearity of this method makes it particularly suitable for optimization tasks. This capability is illustrated using the ITER ELM mitigation coil system, which possesses 27 degrees of freedom.