Largeur de SOL turbulente dans les plasmas circulaires: un modèle théorique validé sur des expériences du tokamak Tore Supra

The relation between turbulent transport and scrape off layer width is investigated in circular plasmas toroidally limited on the inner wall. A broad range of experimental observations collected in the Tore Supra scrape off layer are detailed and compared to turbulent interchange models. Blob velocities agree reasonably well with an analytical model derived for isolated blobs. A set of 2D isothermal turbulence simulations are used to derive a scaling law for the density width. Quantitative agreement is found between this model scaling and experimental density width measured in Tore Supra, over a large set of plasma conditions. The sensitivity to control parameters (major radius, safety factor and normalized Larmor radius) is roughly explained by the sensitivity of the blob velocity model. The predictions are also extended to power decay length in limited plasma configurations. For ITER start-up phases, the predicted power decay length fall in the range of extrapolations based on multi-machine regressions