OBSERVATION OF TEMPERATURE-DEPENDENT TRANSPORT IN THE TFTR TOKAMAK

Local particle and heat transport coefficients have been measured in a temperature scan of neutral-beam-heated plasmas with n, I(p), and B-phi held constant. The electron transport is ascertained from a flux analysis of a small density perturbation, and the heat transport is obtained from the equilibrium power balance. The transport coefficients vary as T-(e)alpha where alpha = 1.5-2.5. The observed temperature dependence is predicted by numerical calculations of anomalous transport due to trapped-particle drift-type microinstabilities.