Short wavelength fluctuations and electron transport in TFTR

Correlation between electron heat diffusivity and short wavelength (k rho (i) similar to 5) fluctuation amplitude was observed in the TFTR tokamak in the cure of ERS plasmas (Phys. Lett. A 236 (1997) 339). These fluctuations propagate in the ion diamagnetic drift direction with wave number comparable to omega (pe)/c Further analysis of these data yields the ratios chi (e)/chi (i) and chi (e)/D-e, and their values are consistent with the picture that the electron transport is mainly induced by the short wavelength fluctuations in the plasma core where the long wavelength (k rho (i) similar to 1) fluctuations are absent. Although there is not enough information to identify these short wavelength modes, the values of chi (e) is found to be comparable to theoretical predictions based on the current diffusive ballooning mode theory (Plasma Phys. Control. Fusion 36 (1994) 279). (C) 2000 Elsevier Science B.V. All rights reserved.