Turbulent particle transport in Tore Supra

Steady state fully non-inductive current plasmas in Tore Supra offer an opportunity to study the turbulent particle pinch. The local parametric dependence of the particle pinch velocity allows us to discriminate between different theories. The existence of an anomalous pinch is unambiguously demonstrated. The results support the turbulent theories based on ion temperature gradient and trapped electron modes. An anomalous inward pinch related to the safety factor (q) profile is found to be dominant in the gradient region (normalized radius 0.3 ≤ r/a ≤ 0.6). In contrast, the direction of the anomalous pinch in the plasma core (r/a ≤ 0.3) is more sensitive to the electron temperature (T_e) profile.