Local transport in joint European Tokamak edge-localized, high-confinementmode plasmas with H, D, DT, and T isotopes

The edge-localized, high-confinement mode regime is of interest for future Tokamak reactors since high performance has been sustained for long duratio ns. Experiments in the Joint European Tokamak [M. Keilhacker et al., Nuclea r Fusion 39, 209 (1999)] have studied this regime using scans with the toro idal field and plasma current varied together in H, D, DT, and T isotopes. The local energy transport in more than fifty of these plasmas is analyzed, and empirical scaling relations are derived for energy transport coefficie nts during quasi-steady state conditions using dimensionless parameters. Ne ither the Bohm nor gyro-Bohm expressions give the shapes of the profiles. T he scalings with beta and nu (*) are in qualitative agreement with Ion Temp erature Gradient theory. (C) 2000 American Institute of Physics. [S1070-664 X(00)02912-8].