Dust magneto-gravitational drift wave in g×B configuration

Abstract

The dispersion relation of electrostatic waves in a magnetized complex plasma under gravity is presented. It is assumed that the waves propagate perpendicular to the external fields. The effects of weak electric field, neutral drag force, and ion drag force are also taken into account. The dispersion relation is numerically examined in an appropriate parameter space in which the gravity plays the dominant role in the dynamics of magnetized microparticles. The numerical results show that an unstable low frequency drift wave can be developed in the long wavelength limit. This unstable mode is transformed into an aperiodic stationary structure at a cut-off wavenumber. Furthermore, the influence of the external fields on the dispersion properties is analyzed. It is shown that the instability is essentially due to the E×B drift motion of plasma particles. However, in the absence of weak electric field, the g×B drift motion of microparticles can cause the instability in a wide range of wavenumbers. It is also found that by increasing the magnetic field strength, the wave frequency is first increased and then decreased. This behaviour is explained by the existence of an extremum point in the dust magneto-gravitational drift velocity.

Dust gravitational drift wave in complex plasma under gravity

“…This phenomenon differs from that predicted for the dust density wave 14 or for the dust magnetogravitational drift wave. 18 In our previous work, 18 we found that in a magnetized complex plasma under gravity, there is a cross-over point at which the propagation of dust magnetogravitational drift wave is suppressed and an aperiodic stationary structure (x ¼ 0; c > 0) is formed. However, in an unmagnetized complex plasma under gravity, we deal with a critical point instead of a cross-over point and the stability switching instead of the stationary structure.…”

“…18 We found that a new low frequency drift wave, named as dust magnetogravitational drift wave, can be developed in the long wavelength limit. This mode is transformed into an aperiodic stationary structure at a cut-off wavenumber.…”