Main Problems under Investigation:Equilibria, Stability and Transport Processes of Plasmas Confined in Strong Three-Dimensional Magnetic Field.
Brief Summary of Recent 3-year Activity :
The aim of the works that were performed was the theoretical investigation of the equilibria, stability and transport properties of three- dimensional (3-D) plasma objects, improvement of the existing and development of new analytical and numerical methods for the solution of the related problems. The free-boundary plasma equilibria were investigated. Particular attention was placed on the analysis of the influence of the plasma induced magnetic fields on the shape and sizes of the plasma boundary. A quick numerical procedure has been developed for the calculation of 3-D plasma induced magnetic fields.
We have considered also some interesting aspects of the influence of the magnetic hump on the values of Pfirsch-Shcluter currents and in particular showed that their values are strongly dependent on the position of the plasma coloumn. The dependencies of plasma induced magnetic fields on the plasma profiles were considered in detail and it was shown that it is possible to extract information on the plasma profiles measuring the external plasma induced magnetic fields. We have developed the conception of none-single-valued flux coordinates for the analysis of the plasma configurations with magnetic islands.
Several methods were proposed to improve stability conditions using local 3-D vacuum magnetic fields. We clarified also the nature of the influence of the plasma induced magnetic fields on the transport properties. The solution to stationary transport equations were found, taking into account both neoclassical and anomalous transport. While studying neoclassical transport we have taken into account the full matrix of transport coefficients. This model was applied to calculate the energy confinement times for all existing stellarators. It was found that the model gives a scaling very similar to so-called LHD scaling. The modeling of plasma edge turbulence has been performed.
Collaboration: CIEMAT(Spain), Moscow State University (Russia).