Divertor

In a tokamak the outer magnetic field lines are diverted to a location far from the plasma by means of a specially shaped magnetic field. In a stellarator the plasma edge splits anyway - in keeping with the symmetry of the magnetic field - into individual offshorts, in which energy and particles move to restricted areas of the vessel wall. Here the field lines contact the vessel wall on specially equipped divertor plates. With this configuration it is possible to produce much purer plasmas, i. e. less contaminated by foreign atoms, that afford much better energy confinement than limiter plasmas.