Core Fluctuations and Non-Thermal Electron Distributions at W7-AS

Two special applications of ECE radiometry at W7-AS, for measurement of temperature fluctuations and non-thermal electron distributions, are presented. In the first case correlation-radiometry is applied. The fluctuation spectra are found to be composed of two components, a diffusive and a turbulent one, with relative levels of 0.L-2o/". The latter one is discussed in the frame of a turbulent mixing process. To investigate non-thermal electron energy distributions a vertical ECE observation geometry allowing for separation of both thermal and suprathermal populations and their time behaviour is used. Experimental results by variation of plasma parameters are shown and compared with simulated spectra.