Dynamics of Core Electron Temperature Fluctuations during Sawtooth Oscillations on TEXT-U

Core electron temperature fluctuations are measured in a tokamak plasma where some degree of time resolution is achieved. There is a strong correlation between the turbulence level and the phase of the sawtooth oscillations. The enhancement in fluctuations at the sawtooth crash is correlated to a steepening of the electron temperature gradient created as the sawtooth heat pulse propagates outward. A global linear relationship between the temperature fluctuation amplitude and the electron temperature gradient scale length is found.