Long-wavelength density turbulence in the TFTR tokamak

Long-wavelength ρi<1) density turbulence has been measured with good spatial localization in the core region of a high temperature tokamak plasma with auxiliary heating. Density fluctuations of n/n>0.5% exist for k<2 cm-1 with radial and poloidal correlation lengths typically 1-2.5 cm in the confinement region, corresponding to kρi0.1-0.3. An anisotropic wave-number spectrum is observed, and estimates of the turbulence-driven transport are comparable to the anomalous transport observed in tokamaks.