The image on the left shows the tokamak and 3D magnetic perturbation generated by 3D coils, with the purple-blue hues representing lower amplitude perturbations and the red representing higher amplitude perturbations. The image on the right is a closer view showing the top half of the tokamak and plasma. The coils are used to generate the magnetic field perturbations that produce the islands (blue). Another coil can also be found on the bottom of the machine. The injection system for the ECCD microwaves is depicted on top (red). These can be used to adjust the width of the islands. (Image: Qiming Hu / PPPL)