Ion drag as a mechanism of plasma dust structure rotation in a strata in a magnetic field

Abstract

In experiments on complex plasmas, afixed strata region in which the levitation of dust structures is observed is investigated using the method of probing by calibrated dust particles of different sizes in an applied magnetic field under elevated pressures. The measured azimuthal velocity of the probing particles corresponds to the action of the ion drag force for 4 μm-size particles and to the entrainment by the rotating gas owing to the electron vortex flow inside the strata for 1 μm-size particles. Extrapolation to pressures and magnetic fields in which the rotation inversion of dust structures is observed in experiments shows that the ion drag is the dominating force causing rotation with a negative projection of the angular velocity onto the magnetic induction.

Complex plasma in glow discharge in a strong magnetic field

“…In this case, the rotation of the dust particles occurs under the drag force action by ions drifting in crossed magnetic (longitudinal) and electric (radial ambipolar) fields. This mechanism was studied in detail in a series of papers [17][18][19][38][39][40][41][42][43]. With the magnetic-field increase, the rotation velocity slows down and drops to zero, at B ≈ 0.027 T the rotation inversion occurs.…”

Observation of the dynamics of the dust structure in a dust trap in a double electric layer in a magnetic field up to 10,000 G

“…A number of studies have identified several physical phenomena associated with the dusty structures, their geometry, their dynamics in a magnetic field, and the ordering of particles. Nowadays, studies of dusty plasmas in magnetic fields continue, and the magnetic field magnitude range has been sufficiently widened .…”