A number of experimental fusion facilities are operated worldwide aimed at the generation of a database for the design of future fusion reactors in particular regarding plasma heating and –confinement as well as material development of plasma facing components. All important fusion devices are working on the tokamak-principle. The tokamak-principle is characterized by a torus-shaped plasma chamber which confines the plasma by three overlapping magnetic fields:
- The toroidal magnetic field generated by the toroidal field coils
- The poloidal magnetic field generated by the plasma current caused by a transformer (therefore a tokamak cannot be operated stationary but only in a pulsed mode), and
- The vertical magnetic field generated by the vertical field coils.
The presently biggest German fusion facility ASDEX upgrade is being operated by the Max-Planck-Institute for Plasma Physics (IPP) according to the tokamak-principle since 1990.
Parallel to the tokamak which releases energy in long pulses the stellarator development is being pursued which allows a continuous plasma operation. Under the overall leadership of the Max-Planck-Institute for Plasma Physics (IPP) the stellarator facility Wendelstein 7-X is being constructed in Greifswald/Germany.