Shown is the iter plasma surface and toroidal magnetic field coils; color contours indicate local magnetic strength at Oak Ridge National Laboratory.
The way structure of the contour lines is caused by deviations from axisymmetry due to thefinite number of toroidal field coils and the presence of ferrite materials in three blanket modules, which are located on one side of the tours. Data for this plot by ORNL's VMEC 3D equilibrium code using profiles for an ITER Scenario 4 Plasma.
Original public domain image from Flickr