A cut through the skeleton of the final magnetic field in the plane z = 0.5 perpendicular to the separator with contours of | j | showing the current layer at the centre. The insert shows the separator current layer’s depth (labelled d) and width (labelled w). On the main plot, lines which cut across the width (dashed, white) and through the depth (solid, white) of the current layer are shown. The length, l_sep, of the current layer (not shown) is directed out of the plane of this cut and is equal to the length of the separator in the final equilibrium.