(Joint European Torus) at Culham, UK is one of the major tokamaks in the world and has produced 16 MW of fusion power in D-T experiments.

In a tokamak, the plasma has a shape like an inflated tube of a car wheel, enclosed in a magnetic cage. The magnetic fields produced by the coils surrounding the plasma as well as by a current driven in the plasma itself, help in confining the hot plasma away from surrounding material walls. The plasma is heated to fusion relevant temperatures (a few hundred million degrees Kelvin!) by injecting high energy neutral particle beam or radio frequency waves from outside which get absorbed in the plasma (Figure 2).