Dynamics of dust structures in a dc discharge under action of axial magnetic field

Abstract

Results of experiments on the formation of dusty plasma structures in a stratified dc discharge in axial magnetic fields up to 2500 G are presented. The rotation of the rather small and planar dusty plasma structures has been observed. As the field increases, the inversion of the structure rotation occurs, and when it reaches 700 G, the displacement of dust particles from the axial region of the discharge to the periphery, along with the rotation continuation, is observed. The explanation of the features in the dynamical behavior of the dust particles in the discharge, in particular the rotation inversion, is proposed.

Superdiffusion of two-dimensional Yukawa liquids due to a perpendicular magnetic field

“…Our paper is motivated by the recent attention given to dusty plasma behavior under magnetic field [32][33][34][35][36][37][38][39][40]. This attention is driven by experiments, which have only recently begun.…”

Streaming Complex Plasmas: Ion Susceptibility for a Partially Ionized Plasma in Parallel Electric and Magnetic Fields

“…By adjusting the magnetic field strength it is possible to create plasma states where only the electrons, electrons and ions, or possibly all three charged particle species including the dust particles are magnetized [4]. Several new phenomena have been observed in experiments with magnetic fields, including a slow rotation of the entire dust cloud [5][6][7][8][9], the spinning of dust particles [10], and complicated flow patterns [11]. In recent experiments with strong magnetic fields on the order of a few Tesla, sufficient to magnetize not only the electrons but the ions as well, filaments appeared in the discharge [12].…”

Detection of eddy current in the striation

“…In the area located in the center of striations (the body of striations) at coordinates from h =5mmtoh = 10 mm in fig. 2 both mechanisms lead particles to rotating in the same direction with negative projection of the angular velocity since eddy current in this area has the component directed radially to the wall of the tube [12][13][14][15]. The assessments of the rotation velocity owing to eddy current and ion drag give the values −(0.15-0.20) rad/sand−0.01 rad/s (for particles of 4.1 µm).…”

“…Probably the most interesting feature of dusty plasma in magnetic field is the complex dynamics of the rotational motion which shows an inversion of the direction angular velocity of the rotation of dust structure. A discovery of this phenomenon in the stratified glow discharge stimulated the emergence of a number of articles discussing possible mechanisms of the inversion of the rotation direction [12][13][14][15][16].…”

“…The mechanism associated with the dragging of the particles by the gas rotating under the influence of the Ampère force caused by the radial component of eddy current directed to the tube axis operates in the area in the head of striations. The value of the angular velocity of the particles can be estimated by the formula from [12][13][14][15],…”