Turbulence and transport in a magnetized plasma column investigated with electrostatic probes and fast imaging

This work is devoted to the characterization of turbulent structures and the induced transport in a magnetized plasma column. Complementary to Langmuir probe measurements, used for local investigation of instability induced turbulent transport, an accurate spatial characterization of structures is achieved using fast imaging of the plasma column's cross-section. The fluctuating light intensity has been linked to density fluctuations of plasma electrons by comparisons with probe measurements and the combined use of interference filters. Processing techniques have been adapted to image data (filtering, extraction of time series, velocimetry). It could be shown that detection of non-linear mode couplings is possible via fast imaging. Simultaneous couplings could be studied at different radii and using wavelet bi-coherence, the temporal evolution of power spectra could be linked with the coupling intensities. (author)