Observation of the coherence between the plasma density fluctuations in the core and at the edge of the plasma column in the L-2M stellarator

Results are presented from the measurements of the radial coherence between the plasma density fluctuations in the core and at the edge of the plasma column in the L-2M stellarator. It is found that the radial coherence betwe en these fluctuations is fairly high: the coherence coefficient attains a v alue of higher than 0.5 for the spectral wavelet components with frequencie s lying in the range from several kilohertz to 30 kHz. The statistical char acteristics of density fluctuations are also studied. It is shown that the power distribution function of the plasma density fluctuations in the plasm a core differs from Gaussian. (C) 2000 MAIK "Nauka/Interperiodica".