LONG-WAVELENGTH DENSITY TURBULENCE IN THE TFTR TOKAMAK

Long-wavelength (k(perpendicular-to)rho(i) < 1) density turbulence has been measured with good spatial localization in the core region of a high temperature tokamak plasma with auxiliary heating. Density fluctu ations of n/n > 0.5% exist for k(perpendicular-to) < 2 cm-1 with radia l and poloidal correlation lengths typically 1-2.5 cm in the confineme nt region, corresponding to k(perpendicular-to)rho(i) almost-equal-to 0.1-0.3. An anisotropic wave-number spectrum is observed, and estimate s of the turbulence-driven transport are comparable to the anomalous t ransport observed in tokamaks.