Long-wavelength density turbulence in the TFTR Tokamak

Long-wavelength ([ital k][sub [perpendicular]][rho][sub [ital i]][lt]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 [ital [tilde n]]/[ital n][gt]0.5% exist for [ital k][sub [perpendicular]][lt]2 cm[sup [minus]1] with radial and poloidal correlation lengths typically 1--2.5 cm in the confinement region, corresponding to [ital k][sub [perpendicular]][rho][sub [ital i]][approx]0.1--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.