Tarasov M. Streams of charged particles in plasma and their fluctuations in linear and toroidal magnetic configurations

In this work the oscillatory and wave processes in charged particles flows together with some features of these flows are studied experimentally at linear and toroidal magnetic confinement devices. In particular the results of the experimental study of ultra high frequency oscillations generation which takes place during the charged particles flow deceleration in the external electric field are presented. The experiments were performed for the flat flow geometry. The measurements were carried out at the regime in which the reverse flow formation wasn't observed. In the framework of the experiments carried out at linear confining devices the stability of cylindrical electron flow injected into a longitudinal magnetic field. The breadth of the flow particles distribution by longitudinal velocities was comparable the average flow velocity. The flow plasma density and temperature was close to the corresponding parameters of the U-3M torsatron edge plasma. The nonlinear behavior of the diocotron waves disturbed during the flow propagation was studied experimentally. The depenedences for such magnitudes as the averaged (over the injection pulse duration) amplitude modulation depth, the averaged (over the diocotron waves frequency band) frequency and also the width of the diocotron waves frequency band on such parameters as average flow velocity, magnetic field strength and also on the introduction of metal electrode. Furthermore the dynamics of so called residual diocotron waves was investigated. The study of the residual plasma state was carried out using the additional injection. The study of non-neutral flow dynamics in the toroidal magnetic field configuration was carried out on the U-3M device which represents a torsatron with triple-threaded magnetic field winding. In particular the runaway particles flow was investigated. The measurement have shown that the flow has both electron and ion components. The work contains the results of X-ray, electrostatic probe, optical and microwave diagnostics measurements which give information about the flow structure, properties and creation mechanism. The ionization processes which were observed together with the flow formation are also described. Special attention was paid to the edge plasma electrostatic fluctuations in the U-3M torsatron. In particular, the study of parametric instability excitation which was observed in the spectrum of the RF-heating frequency harmonics was carried out. The possibility of interaction between such fluctuations and the runaway particles was also studied.