Long-wavelength density turbulence in the TFTR tokamak

Long-wavelength (k_⊥{{{ρ}}}ᵢ$1) density turbulence has been measured with good spatial localization in the core region of a high temperature tokamak plasma with auxiliary heating. Density fluctuations of n ̃ \~{}{}/n>0.5% exist for k_⊥2 cm^-1 with radial and poloidal correlation lengths typically 1--2.5 cm in the confinement region, corresponding to k_⊥{{{ρ}}}ᵢ${}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.