Design of the JET pumped divertor

The JET (Joint European Torus) pumped divertor aims at demonstrating an effective method of impurity control with quasi-stationary plasmas of thermonuclear grade in a next step relevant, axisymmetric configuration. The magnetic configuration is produced by a set of four coils internal to the JET vacuum vessel. These coils can produce a range of configurations and also sweep the magnetic field lines along the target plates. The target plates will initially use radiation-cooled beryllium tiles, but actively cooled target plates able to operate in steady state at up to 40 MW are planned in a second phase. The design also features a cryopump which will remove a fraction of the particles recycled in the vicinity of the target plates. The configuration of the ICRH (ion cyclotron resonance heating) antennae and wall protections has been modified to match the new plasma shape. All components have been designed to resist the large forces generated by halo currents. >