Particle balance in Tore Supra for ohmic discharges

The particle balance in the plasma core of TS is investigated for ohmic deuterium discharges leaning on the inner wall. The neutral density profile is deduced from the simulation of charge exchange fast neutral spectra. The resulting neutral density, which depends principally on the hot charge exchange neutrals, is compared to a neutral transport calculation assuming a diffusive approximation in the central part of the plasma and a non-local slab description at the plasma edge. Diffusion and convection coefficients are then deduced by fitting the electron and neutral density values. It is shown that these coefficients follow an Alcator like dependence at low density, then saturate at higher density, similar to the heat conduction coefficient. At high density, the ratio between the heat and particle diffusion coefficients is equal to 4-3. Particular attention is also given to the particle confinement time. (author) 8 refs., 8 figs