Fluctuations of electron density and temperature in the hot pedestal are investigated in-between type-I edge localized modes (ELMs) by high resolution, high precision Thomson scattering. The observed fluctuations of electron density and temperature are correlated and in phase. The amplitudes of these fluctuations become observable above a line-averaged electron density of about 4 × 1019 m−3. The heat transport in the pedestal is investigated by analysing the heat diffusivity. The experimentally found variations in the relative fluctuation amplitudes of electron density and temperature and of the heat diffusivity can be explained by different scale lengths of the underlying turbulence. The large fluctuations of electron density and temperature scale with a hybrid scale between ideal and resistive magneto-hydrodynamics, while the thermal transport occurs on the smallest scale lengths of the turbulence.
Testing instabilities and microturbulence in TEXT