Collisional effects on the electrostatic dust cyclotron instability

1999 ◽  
Vol 61 (1) ◽  
pp. 51-63 ◽  
Author(s):  
M. ROSENBERG ◽  
V. W. CHOW
Keyword(s):  
Magnetic Field ◽  
Kinetic Analysis ◽  
Dusty Plasma ◽  
Charged Dust ◽  
Cyclotron Instability ◽  
Weakly Ionized ◽  
The Magnetic Field ◽  
A Current

A kinetic analysis of the electrostatic dust cyclotron instability in a weakly ionized collisional dusty plasma is presented. In a plasma with negatively charged dust and a current along the magnetic field B, it is found that the instability can be excited by ions drifting along B. The effect of dust–neutral collisions is stabilizing, while the effect of ion–neutral collisions can be destabilizing. Possible applications to laboratory environments are discussed.

scholarly journals Simulations of a low frequency beam-cyclotron instability in a dusty plasma

2018 ◽  
Vol 84 (6) ◽  
Author(s):  
M. Rosenberg ◽  
K. Quest ◽  
B. Kercher
Keyword(s):  
Magnetic Field ◽  
Dusty Plasma ◽  
Low Frequency ◽  
Dusty Plasmas ◽  
Charged Dust ◽  
Particle In Cell ◽  
Nonlinear Development ◽  
Cyclotron Instability ◽  
Wavenumber Spectrum ◽  
The Magnetic Field

The nonlinear development of a low frequency beam-cyclotron instability in a collisional plasma composed of magnetized ions and electrons and unmagnetized, negatively charged dust is investigated using one-dimensional particle-in-cell simulations. Collisions of charged particles with neutrals are taken into account via a Langevin operator. The instability, which is driven by an ion $\boldsymbol{E}\times \boldsymbol{B}$ drift, excites a quasi-discrete wavenumber spectrum of waves that propagate perpendicular to the magnetic field with frequency of the order of the dust plasma frequency. In the linear regime, the unstable wavelengths are of the order of the ion gyroradius. As the wave energy density increases, the dominant modes shift to longer wavelengths, suggesting a transition to a Hall-current-type instability. Parameters are considered that reflect the ordering of plasma and dust quantities in laboratory dusty plasmas with high magnetic field. Comparison with the nonlinear development of this beam cyclotron instability in a collisionless dusty plasma is also briefly discussed.

Ambipolar electrostatic field in negatively charged dusty plasma

2021 ◽  
Author(s):  
Lina Hadid ◽  
Oleg Shebanits ◽  
Jan-Erik Wahlund ◽  
Michiko Morooka ◽  
Andrew Nagy ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Dusty Plasma ◽  
Transport Processes ◽  
Clear Correlation ◽  
Charged Dust ◽  
Polarization Electric Field ◽  
F Ring ◽  
The Magnetic Field

<p>It is well known that in the magnetosphere of the outer planets (eg. Saturn, Jupiter, Neptune), even in the absence of an electric current, a polarization electric field develops as a consequence of charge separation in a plasma, providing a restoring force to maintain charge neutrality. It is also well established that certain regions of these planetary systems (ionosphere, icy moons, rings) are populated by significant amount of charged dust that play an important role in the physical and chemical processes in the surrounding plasma environment.<br>In the present work, we study the effect of the charged dust grains on the polarization electric field using Saturn’s F-ring region as a case study. We derive a general expression for E parallel to the magnetic field (E_para) and then using the Cassini RPWS/LP measurements we estimate for the first time in situ E_para close to Janus/Epimetheus ring during the F ring grazing orbits. We further demonstrate that the presence of charged dust,  as small as nanometers in size, can significantly influence the plasma transport processes, in particular the ambipolar diffusion along the magnetic field lines. We show that, close to the ring plane (Z <0.1 Rs), the dusty plasma amplifies E_para by at least one order of magnitude and reverses its direction. Such a reversal implies a confinement of the electrons above the equatorial plane. Furthermore, we show a clear correlation between the amplification of the ambipolar eletrostatic field and the ions and electrons number densities, that could be used in other dusty environments where in-situ measurements are not available yet (in our solar system or the interstellar medium).</p>

Nonlinear Alfvén Waves in Weakly Ionised Dusty Plasmas

2001 ◽  
Vol 18 (4) ◽  
pp. 374-383 ◽  
Author(s):  
N. F. Cramer ◽  
J. I. Sakai ◽  
S. V. Vladimirov
Keyword(s):  
Magnetic Field ◽  
Dusty Plasma ◽  
Dusty Plasmas ◽  
Transverse Magnetic ◽  
Alfven Waves ◽  
Ambipolar Diffusion ◽  
Alfvén Waves ◽  
Charged Dust ◽  
Single Plane ◽  
The Magnetic Field

AbstractThe effects of charged dust on the steepening of the fields in nonlinear Alfvén waves in astrophysical weakly ionised plasmas are investigated. It is found that the formation of current singularities in the wave due to nonlinear ambipolar diffusion is strongly modified by the effects of the dust. The basic modes for propagation along the magnetic field in a dusty plasma are highly dispersive and split by the anisotropy of the magnetic field into two modes that are oppositely circularly polarised rather than linearly polarised. The right hand circularly polarised wave experiences a cutoff due to the presence of the dust. We derive nonlinear fluid equations describing the dusty plasma, and make approximations for strong coupling of the dust to the neutrals, and for stationary dust. Numerical solution of the equations shows that a nonlinear wave with sharp current features due to ambipolar diffusion involves a rotation of the wave magnetic field about the direction of propagation, and an oscillation of the field components, due to the mode splitting effects of the dust. This is in contrast to the dust-free case, where the sharp reversal of the transverse magnetic field component occurs in a single plane.

Nonlinear dynamics of the filamentation of the resistive instability of a current-carrying plasma

2008 ◽  
Vol 74 (3) ◽  
pp. 319-326 ◽  
Author(s):  
A. R. NIKNAM ◽  
B. SHOKRI
Keyword(s):  
Magnetic Field ◽  
Neutral Current ◽  
Density Variation ◽  
Nonlinear Regime ◽  
Field Diffusion ◽  
Weakly Ionized ◽  
Electron Density Variation ◽  
Sinusoidal Shape ◽  
The Magnetic Field ◽  
A Current

AbstractThe filamentation of the resistive instability in a weakly ionized quasi-neutral current-carrying plasma in the diffusion frequency region in the nonlinear regime is investigated. By using the magnetohydrodynamics equations and Ampere's law and assuming that the plasma is non-isothermal and inhomogeneous, the evolution of the magnetic field diffusion into the plasma is described by the Lienard nonlinear differential equation. Furthermore, it is shown that the departure of the profiles of the magnetic field and electron density variation from a sinusoidal shape in the nonlinear regime and a transverse filamentation and density steepening can occur in the static limit. Also, it is shown that the shape of the transverse filamentation can vary in this regime depending on the gradient of the magnetic field.

Study of MFM Application in Semiconductor Failure Analysis

2004 ◽  
Author(s):  
Way-Jam Chen ◽  
Lily Shiau ◽  
Ming-Ching Huang ◽  
Chia-Hsing Chao
Keyword(s):  
Magnetic Field ◽  
Failure Analysis ◽  
Magnetic Force Microscopy ◽  
Magnetic Force ◽  
Current Flow ◽  
Force Microscopy ◽  
The Magnetic Field ◽  
A Current

Abstract In this study we have investigated the magnetic field associated with a current flowing in a circuit using Magnetic Force Microscopy (MFM). The technique is able to identify the magnetic field associated with a current flow and has potential for failure analysis.

Particle Transport in a Turbulent Square Duct Flow With an Imposed Magnetic Field

2013 ◽  
Author(s):  
Rui Liu ◽  
Surya P. Vanka ◽  
Brian G. Thomas
Keyword(s):  
Magnetic Field ◽  
Particle Transport ◽  
Continuous Flow ◽  
Duct Flow ◽  
Deposition Rates ◽  
Square Duct ◽  
Side Walls ◽  
Volume Method ◽  
The Magnetic Field ◽  
A Current

In this paper we study the particle transport and deposition in a turbulent square duct flow with an imposed magnetic field using Direct Numerical Simulations (DNS) of the continuous flow. A magnetic field induces a current and the interaction of this current with the magnetic field generates a Lorentz force which brakes the flow and modifies the flow structure. A second-order accurate finite volume method in time and space is used and implemented on a GPU. Particles are injected at the entrance to the duct continuously and their rates of deposition on the duct walls are computed for different magnetic field strengths. Because of the changes to the flow due to the magnetic field, the deposition rates are different on the top and bottom walls compared to the side walls. This is different than in a non-MHD square duct flow, where quadrant (and octant) symmetry is obtained.

scholarly journals The study of the specific resistance of bismuth crystals and its change in strong magnetic fields and some allied problems

1928 ◽  
Vol 119 (782) ◽  
pp. 358-443 ◽  
Keyword(s):  
Magnetic Field ◽  
Specific Resistance ◽  
Cleavage Plane ◽  
Time Lag ◽  
General View ◽  
Time Lags ◽  
Strong Magnetic Fields ◽  
First Moment ◽  
The Magnetic Field ◽  
A Current

It is well known that in a magnetic field bismuth shows a greater change of resistance than any other substance, and it is also known that in the case of a crystal this phenomenon varies very much with the orientation of the crystal. A great deal of literature exists on this subject. The general view of the phenomenon is that the increase of resistance is largest when the cleavage plane of the crystal is parallel to the magnetic field, and when the current is flowing perpendicular to it. It is also known that the resistance in a magnetic field increases very rapidly with decreasing temperature. A complication in all these phenomena arises through certain time lags. When a current is passed through bismuth placed in a magnetic field, the resistance at the first moment is large, and then gradually decreases to its final value. This time lag accounts for the fact, first discovered by Lenard, that bismuth has a larger resistance for alternating currents than for direct currents. This phenomenon also depends on the crystal state of the bismuth.

scholarly journals XII. A new current weigher and a determination of the electromotive force of the normal Weston cadmium cell

1908 ◽  
Vol 207 (413-426) ◽  
pp. 463-544 ◽  
Keyword(s):  
Magnetic Field ◽  
Magnetic System ◽  
Electric Circuit ◽  
Secular Variations ◽  
System Of Units ◽  
Electro Magnetic ◽  
The Magnetic Field ◽  
A Current ◽  
Mutual Action

A Current can be measured absolutely in the electro-magnetic system of units either by means of the action of the current on a magnet, or of the current on a current. The former method has the disadvantage that at least two independent measurements are necessary. For example, in using an electro-magnetic balance, the strength of the magnet acted on by the electric circuit has to be determined, as well as the force exerted on the magnet by the circuit. In galvanometers, either of the sine or tangent type, the magnetic field produced by the electric circuit is compared with the earth’s horizontal field, the strength of which is determined independently. Further, as the strength of artificial magnets cannot be regarded as truly constant, and the earth’s field is subject to diurnal and secular variations, this class of measurement is not ideal. In the electrodynamic class of measurement the mutual action between two or more coils carrying current takes the form of a torque, as in electrodynamometers, or a direct force, as in current weighers. In electrodynamometers the torque may be measured with a bifilar suspension, the torsion of a wire or spring, or by means of a gravity balance. Current weigher measurements are almost always made by direct comparison with gravity, which is believed to be constant, and is known to a higher degree of accuracy than the strengths of any magnet or magnetic field that has yet been measured.

Sign in / Sign up

Export Citation Format

Share Document