Understanding edge tokamak plasma turbulence through direct comparison of interchange model with experiments Project ID: EDGETURB 044830 Provider: Euratom Period: Jan 01, 2007 - Jun 30, 2008 Principal Investigator: Mgr. Jan Horáček, Ph.D. Co-investigators Aims of the project: Boundary plasma interaction with the inner wall of a tokamak determines strongly operation of a future thermonuclear fusion reactor, such as ITER. Just recently, we demonstrated that turbulence model ESEL (from Denmark) quantitatively describes most aspects of the edge plasma turbulent transport near the wall. Experiments on both the Czech Castor and Swiss TCV tokamaks will be conducted with the aim to further improve the ESEL model with the final goal to make it predictive for the future ITER tokamak. Progress/Results: Overall, the research conducted during 18 months directly lead to co-authorships of 7 peer-reviewed journal publications and 13 conference/workshop presentations. We conducted experiments on Czech tokamak Castor: we explained frequency of the 'relaxation phenomena' and found Gamma-like distribution of plasma fluctuations. Large experimental campaing on the Swiss tokamak TCV demonstrated that collisionality is the determining parameter for edge plasma transport. We also finished comparison of measured parallel plasma flows with theory. I developed new technique for fast temperature measurement, applied on comparison with model of ELM instability. Concerning simulations with ESEL model, we predicted existence of a new transport barrier. Attempts to simulate the ITER edge plasma by the ESEL model failed because of too low collisionality.