Temperature fluctuations and their correlation with density fluctuations in W7-AS

Correlations between electron density and temperature fluctuations have been measured in the core plasma of W7-AS. The simultaneous use of transmitting and receiving antennas of a heterodyne reflectometer by a crossed sightline ECE correlation radiometer enables the cross-correlation analysis of the reflectometer phase signal and ECE radiation temperature signals in overlapping plasma volumes. Correlations have been found in the spectral range 25–100 kHz, indicating an in-phase correlation between electron density and temperature fluctuations.