Steady-state hollow electron temperature profiles in the Rijnhuizen Tokamak Project

In the Rijnhuizen Tokamak Project steady-state hollow electron temperature (T-e) profiles have been sustained with strong off-axis electron cyclotron heating, creating a region of reversed magnetic shear. pb In this region the effective electron thermal diffusivity (chi e(Pb)) is close to neoclassical in high density plasmas. For medium density, chi e(Pb) is lower than neoclassical and may even be negative, indicating that off-diagonal elements in the transport matrix drive an electron heat flux up the T-e gradient.