The change in edge fluctuations synchronized with a heat pulse during Sawtooth oscillation has been investigated in the JFT-2M tokamak using a reciprocating Langmuir probe. Data window of a heat pulse is segmented into a number of time frames, and time traces of auto-power spectra at each frame are calculated. Conditional averaging over a number of heat pulse events in a single discharge is performed in order to reduce the variance of the fluctuation spectra. At each heat pulse event, a reduction in the geodesic acoustic mode fluctuation power and an increase in the turbulence fluctuation power are observed. The change in the fluctuation powers suggests that the edge heat pulse during Sawtooth instability could affect the edge turbulence structure.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)