Spatiotemporal control and synchronization of flute modes and drift waves in a magnetized plasma column

Abstract

An open-loop spatiotemporal synchronization method is applied to flute modes in a cylindrical magnetized plasma. It is demonstrated that synchronization can be achieved only if the exciter signal rotates in the same direction as the propagating mode. Moreover, the efficiency of the synchronization is shown to depend on the radial properties of the instability under consideration. It is also demonstrated that the control disposition can alternatively be used to produce strongly developed turbulence of drift waves or flute instabilities.

Nonlinear interaction of drift waves with driven plasma currents

“…Different from previous spatiotemporal control experiments on drift waves [14,15] the exciter setup in this paper uses much smaller electrodes (5 × 20 mm) with respect to the total plasma size (l = 4 m, d = 0.4 m). The perturbation by the control signal on the plasma is well localized.…”

“…Drift waves have been controlled by closedloop schemes using simple feedback methods with rela- * present address: christian.brandt@lpmi.uhp-nancy.fr tively strong perturbations of the plasma [11,12]. Openloop control schemes with predefined space-time signals achieve synchronization of drift waves at smaller perturbation amplitudes [13][14][15]. In the present paper synchronization of drift waves is investigated using a space-time open-loop control system.…”

Selective formation of turbulent structures in magnetized cylindrical plasmas

“…3 Plasma experiments in a simple linear configuration have been revisited recently for quantitative understandings of the structural formation mechanism by turbulence. [4][5][6][7][8][9][10][11][12] A density gradient drives the drift wave turbulence in these plasmas. Two-dimensional measurements reveal the feature of turbulent structures 13,14 and their formation mechanisms by nonlinear mode coupling.…”

Selection rule for turbulent structural formation: study of magnetized cylindrical plasmas

“…Drift wave turbulence is driven by the density gradient, which is universal in confined plasmas, and has been observed in linear configurations [7,8,15]. Two-dimensional measurements have revealed the feature of turbulent structures [16,17] and their formation mechanisms by mode coupling [15,18].…”

“…Plasma experiments in a simple linear configuration have been revisited recently for quantitative understandings of the structural formation mechanism by turbulence [6][7][8][9][10][11][12][13][14]. Drift wave turbulence is driven by the density gradient, which is universal in confined plasmas, and has been observed in linear configurations [7,8,15].…”