Dust and plasma properties measured using two confined particles

2016 ◽  
Vol 82 (3) ◽  
Author(s):  
T. E. Sheridan ◽  
Nicholas R. Weiner ◽  
Thomas E. Steinberger
Keyword(s):  
Dust Particles ◽  
Plasma Properties ◽  
Effective Electron ◽  
Sheath Edge ◽  
Dust Charge ◽  
Debye Shielding ◽  
Vertical Electric Field ◽  
Effective Electron Temperature ◽  
Plasma Measurements ◽  
Radio Frequency Discharge

We consider two isolated, interacting dust particles confined in plasma. Measurements of normal mode frequencies are used to determine the dust charge, the Debye shielding length and the anisotropy of the confining potential well. For dust particles confined near the sheath edge, the vertical electric field and an effective electron temperature are also determined. This method is used to characterize the sheath above a short rectangular trench in the powered electrode of a radio-frequency discharge.

scholarly journals EFFECTS OF ARGON ATOMS IN EXCITED STATES ON PROPERTIES OF ARGON-ACETYLENE DUSTY PLASMA

2020 ◽  
pp. 26-29
Author(s):  
I.B. Denysenko ◽  
S. Ivko ◽  
N.A. Azarenkov ◽  
G. Burmaka
Keyword(s):  
Electron Temperature ◽  
Dusty Plasma ◽  
Excited States ◽  
Plasma Volume ◽  
Numerical Calculations ◽  
Dust Particles ◽  
Neutral Species ◽  
Effective Electron ◽  
Effective Electron Temperature ◽  
Averaged Model

It is studied how dissociation and ionization of acetylene molecules in their collisions with argon atoms in excited states Ar* may affect properties of argon-acetylene plasma with growing inside of plasma volume dust particles. The study is carried out using a volume-averaged model. To analyze the effects of Ar* atoms on the electron and ion densities, the effective electron temperature and the densities of radical and nonradical neutral species, the values of ionization and dissociation rates for collisions of acetylene molecules with Ar* atoms are varied in numerical calculations. It is found that the collisions of Ar* atoms with acetylene molecules affect essentially the argon-acetylene dusty plasma.

Effect of q-non-extensive distribution of electrons on the plasma sheath floating potential

2014 ◽  
Vol 80 (4) ◽  
pp. 607-618 ◽  
Author(s):  
M. Sharifian ◽  
H. R. Sharifinejad ◽  
M. Borhani Zarandi ◽  
A. R. Niknam
Keyword(s):  
Electron Temperature ◽  
Electron Distribution ◽  
Plasma Sheath ◽  
The Other ◽  
Floating Potential ◽  
Effective Electron ◽  
Debye Shielding ◽  
Unmagnetized Plasma ◽  
Sheath Phenomena ◽  
Effective Electron Temperature

In this paper, a collisionless unmagnetized plasma sheath consisting of electrons following non-extensive q-distribution, and cold mobile inertial ions is studied in the stationary state. In this type of plasma with non-Maxwellian electron distribution (Tsallis statistical mechanics), the effective electron temperature (Te, eff) and electron screening temperature (Te,*) are evaluated. The other plasma sheath phenomena such as the Bohm sheath criterion, Debye shielding, floating potential, and sheath length are investigated in the presence of q-non-extensive velocity-distributed electrons. It is observed that above-mentioned phenomena depend significantly on the non-extensive parameter q.

scholarly journals A new method of inferring the size, number density, and charge of mesospheric dust from its in situ collection by the DUSTY probe

2019 ◽  
Vol 12 (3) ◽  
pp. 1673-1683 ◽  
Author(s):  
Ove Havnes ◽  
Tarjei Antonsen ◽  
Gerd Baumgarten ◽  
Thomas W. Hartquist ◽  
Alexander Biebricher ◽  
...  
Keyword(s):  
New Method ◽  
Production Model ◽  
Dust Particles ◽  
Bottom Plate ◽  
Charged Dust ◽  
Fundamental Parameters ◽  
Dust Charge ◽  
Analysis Technique ◽  
June July ◽  
The Impact

Abstract. We present a new method of analyzing measurements of mesospheric dust made with DUSTY rocket-borne Faraday cup probes. It can yield the variation in fundamental dust parameters through a mesospheric cloud with an altitude resolution down to 10 cm or less if plasma probes give the plasma density variations with similar height resolution. A DUSTY probe was the first probe that unambiguously detected charged dust and aerosol particles in the Earth's mesosphere. DUSTY excluded the ambient plasma by various biased grids, which however allowed dust particles with radii above a few nanometers to enter, and it measured the flux of charged dust particles. The flux measurements directly yielded the total ambient dust charge density. We extend the analysis of DUSTY data by using the impact currents on its main grid and the bottom plate as before, together with a dust charging model and a secondary charge production model, to allow the determination of fundamental parameters, such as dust radius, charge number, and total dust density. We demonstrate the utility of the new analysis technique by considering observations made with the DUSTY probes during the MAXIDUSTY rocket campaign in June–July 2016 and comparing the results with those of other instruments (lidar and photometer) also used in the campaign. In the present version we have used monodisperse dust size distributions.

Effects of charge dispersion in dusty plasmas

1995 ◽  
Vol 54 (3) ◽  
pp. 373-391 ◽  
Author(s):  
T. K. Aslaksen
Keyword(s):  
Charge Distribution ◽  
Dusty Plasmas ◽  
Dust Particles ◽  
Dust Charge ◽  
Kinetic Effects ◽  
Current Equation

We investigate the charge-dispersive effects on a sheath of monosized dust particles in equilibrium. This is done through describing the dust particles by using equations in (x, v) space (kinetic space) that include terms originating from the charge distribution of the dust particles. The charge-dispersive terms are assumed to be completely determined by the local charging processes. We find that the effects due to these terms are opposed by the ordinary gradient terms in the current equation in kinetic space, and they are therefore smaller than first expected. We also identify kinetic effects that are not included in the usual expression for the dust charge in hydrodynamic space.

Ion transport in electrode sheath with non-uniform dusts

2002 ◽  
Vol 68 (4) ◽  
pp. 249-255
Author(s):  
A. P. SUN ◽  
X. M. QIU ◽  
H. H. TONG ◽  
Q. C. CHEN
Keyword(s):  
Ion Transport ◽  
Dust Particles ◽  
Uniform Density ◽  
Key Factors ◽  
Ion Density ◽  
Factors Affecting ◽  
Dust Density ◽  
Dust Charge ◽  
The Monte Carlo Method ◽  
Electrode Sheath

The Monte Carlo method is used to simulate ion transport in an Ar plasma electrode sheath with a non-uniform dust. Charge exchange and elastic collisions between ions and neutral atoms and also the collection and Coulomb scattering of ions on the dust particles are examined during the motion of ions in the sheath. In order to study the effect of the non-uniform dust density and size on ion transport, we choose an exponent dust density distribution with a uniform dust size and a normal dust radius distribution with a uniform density and compare the simulation results with those for a uniform dust. It is found that both a non-uniform and a uniform dust density affect the ion density arriving at the electrode significantly and to the same degree. At the same time, it is also found that a non-uniform and uniform dust size influence the ion density arriving at the electrode greatly, but with a slight difference. Therefore, although the dust content is very low in most processing plasmas, its influence becomes evident whether its content is uniform or non-uniform in content and size. So, we can come to the conclusion that the key factors affecting the influence of dust particles on plasma behaviour are the linear density and the average radius of dust particles rather than their distribution.

scholarly journals Mesospheric dust and its secondary effects as observed by the ESPRIT payload

2009 ◽  
Vol 27 (3) ◽  
pp. 1119-1128 ◽  
Author(s):  
O. Havnes ◽  
L. H. Surdal ◽  
C. R. Philbrick
Keyword(s):  
Charge Density ◽  
Lower Layer ◽  
Bound Water ◽  
Impact Angle ◽  
Dust Particles ◽  
Height Range ◽  
Dust Layer ◽  
Water Ice ◽  
Dust Charge ◽  
The Impact

Abstract. The dust detector on the ESPRIT rocket detected two extended dust/aerosol layers during the launch on 1 July 2006. The lower layer at height ~81.5–83 km coincided with a strong NLC and PMSE layer. The maximum dust charge density was ~−3.5×109 e m−3 and the dust layer was characterized by a few strong dust layers where the dust charge density at the upper edges changed by factors 2–3 over a distance of ≲10 m, while the same change at their lower edges were much more gradual. The upper edge of this layer is also sharp, with a change in the probe current from zero to IDC=−10−11 A over ~10 m, while the same change at the low edge occurs over ~500 m. The second dust layer at ~85–92 km was in the height range of a comparatively weak PMSE layer and the maximum dust charge density was ~−108 e m−3. This demonstrates that PMSE can be formed even if the ratio of the dust charge density to the electron density P=NdZd /n_e≲0.01. In spite of the dust detector being constructed to reduce possible secondary charging effects from dust impacts, it was found that they were clearly present during the passage through both layers. The measured secondary charging effects confirm recent results that dust in the NLC and PMSE layers can be very effective in producing secondary charges with up to ~50 to 100 electron charges being rubbed off by one impacting large dust particle, if the impact angle is θi≳20–35°. This again lends support to the suggested model for NLC and PMSE dust particles (Havnes and Næsheim, 2007) as a loosely bound water-ice clump interspersed with a considerable number of sub-nanometer-sized meteoric smoke particles, possibly also contaminated with meteoric atomic species.

Analysis of the interaction between particles in non-ideal quasi-equilibrium extended systems

2010 ◽  
Vol 76 (3-4) ◽  
pp. 593-602
Author(s):  
O. S. VAULINA ◽  
E. A. LISIN ◽  
A. V. GAVRIKOV ◽  
O. F. PETROV ◽  
V. E. FORTOV
Keyword(s):  
Inverse Problem ◽  
Radio Frequency ◽  
Dusty Plasma ◽  
Statistical Physics ◽  
Dust Particles ◽  
Langevin Equations ◽  
Quasi Equilibrium ◽  
Experimental Application ◽  
Extended Systems ◽  
Radio Frequency Discharge

AbstractTwo techniques for the analysis of the interaction between particles in non-ideal quasi-equilibrium extended systems are considered. The first technique is based on a solution of the inverse problem describing the movement of dust particles by a system of Langevin equations. The second technique proceeds from the basic integral approaches of statistical physics. The conditions for the correct use of these techniques are presented, together with the results of their experimental application for the analysis of inter-grain interactions in the dusty plasma of radio frequency discharge.

Small-amplitude electrostatic solitary waves in a dusty plasma with variable charge resonant trapped dust particles

2007 ◽  
Vol 73 (6) ◽  
pp. 901-910 ◽  
Author(s):  
LEILA AIT GOUGAM ◽  
MOULOUD TRIBECHE ◽  
FAWZIA MEKIDECHE
Keyword(s):  
Solitary Waves ◽  
Small Amplitude ◽  
Charge Trapping ◽  
Dusty Plasmas ◽  
Dust Particles ◽  
Plasma Parameters ◽  
Variable Charge ◽  
Dust Charge ◽  
Temperature Equilibrium ◽  
Dust Grain

AbstractSmall-amplitude electrostatic solitary waves are investigated in unmagnetized dusty plasmas with variable charge resonant trapped dust particles. It is found that under certain conditions spatially localized structures, the height and nature of which depend sensitively on the plasma parameters, can exist. The effects of dust grain temperature, equilibrium dust charge, trapping parameter, and dust size on the properties of these solitary waves are briefly discussed. A neural network with a given architecture and learning process, and which may be useful to interpret experimental data, is outlined. Our investigation may be taken as a prerequisite for the understanding of the solitary dust waves that may occur in space as well as in laboratory plasmas.

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