6.1. Topology

If you are using the GUI, this page corresponds to the process that happens when the geqdsk file with equilibrium magnetic data is loaded, which should result in a figure something like the figure at the bottom of this page <equilibrium-fig> being shown in the right panel.

The grid generation process begins with TokamakEquilibrium loading the equilibrium data (see Magnetic equilibrium).

The primary O-point and one or two primary X-points are identified, checking how many X-points exist within the \(\psi_N=(\psi-\psi_\mathrm{core})/(\psi_\mathrm{SOL}-\psi_\mathrm{core})\) value specified for the outer radial boundary of the grid.

Critical points

The O-point (blue plus) and X-points (red crosses).

Starting from the X-point(s) the separatrices are traced along the divertor legs to the wall, and around the core points are placed along the separatrix (for a single null or connected double null) or onto a \(\psi\) value that interpolates between those of the primary and secondary X-points, so that the resulting line connects the two X-points. The resulting points are used to construct a set of EquilibriumRegion <hypnotoad.core.equilibrium.EquilibriumRegion objects, one for each region, which provide the skeleton from which the grid is built.

Collection of EquilibriumRegion objects

An Equilibrium contains a set of EquilibriumRegion objects.