Abstract
A periodic enhancement of the microturbulence level by sawtooth relaxations has been detected by CO2 laser forward scattering in the TEXTOR tokamak. This feature is reproduced quantitatively by a heat transport code in which the anomalous electron transport coefficient is calculated self-consistently, following a theoretical model of the saturation of the dissipative trapped electron instability. The code also predicts a strong modulation of the heat flux throughout the plasma and a strong 'profile consistency' as demonstrated elsewhere by continuous temperature measurements. A simple interpretation of these results is given. The calculated global plasma parameters, such as the energy confinement time and the loop voltage, are in good agreement with the measured values.