The Fusion Experiment TEXTOR-94

The physics research program at the Tokamak TEXTOR-94 has the objective of contributing to the development of a coherent concept for the dissipation of energy and particles from magnetically contained fusion plasma. Starting from the knowledge that the complex system of a plasma is determined by the non-linear interactions between the hot plasma core and the surrounding vessel walls and the confinement elements, the Trilateral Euregio Cluster consisting of the FOM-Instituut voor Plasmafysica 'Rijnhuizen', Nieuwegein, The Netherlands, the Royale Militaire/Koninklijke Militaire School, Brussels, Belgium and the Forschungszentrum Juelich GmbH, Juelich, Germany, is investigating the physical processes of plasma heating, particle and energy transport away from the plasma and the resulting plasma-wall interaction. The most important result from this collaboration in the discovery of a plasma state with improved energy containment and a radiating cold plasma mantle at high fuel densities whose characteristic properties emphasise the significance of the interaction between plasma core, plasma peripheral layer and the plasma wall. New experimental setups such as the Dynamic Ergodic Divertor provide the means for the optimisation of this concept. Coils on the inner side of the vacuum vessel overlay a radial interference field over the containing magnet field which leads to a selective magnetic vorticity of the periphery of the plasma. With this method, the hot plasma interior can be shielded from impurities by increased radial transport in this zone. Rotation of the interference field with frequencies of up to 10 kHz create a torque and (differential) rotation of the plasma column which are expected to have a positive effect on plasma stability and energy containment. (orig.)