Long-wavelength density turbulence in the TFTR tokamak

Abstract

Long-wavelength (${\mathit{k}}_{\mathrm{\perp }}$ ${\mathrm{\rho }}_{\mathit{i}}$0.5% exist for ${\mathit{k}}_{\mathrm{\perp }}$<2 ${\mathrm{cm}}^{\mathrm{-}1}$ with radial and poloidal correlation lengths typically 1–2.5 cm in the confinement region, corresponding to ${\mathit{k}}_{\mathrm{\perp }}$ ${\mathrm{\rho }}_{\mathit{i}}$≊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.