Probe induced voids in a dusty plasma

Thomas, E.; Khare, Avinash; Merlino, R. L.

doi:10.1063/1.1688333

Cited by 49 publications

(55 citation statements)

References 17 publications

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“…It has been discussed that dust grains absorb free electrons and reduce the density of free electrons in a plasma. It has been noticed in earlier studies as well in present study that the electrostatic probes modify the dynamics of dust grains in a local region [5,53,54] and cannot be used to measure the plasma parameters and E-field during the wave motion. It has been assumed that plasma parameters are not strongly affected by the dust grains if P h < 1 and plasma parameters can be used to estimate the dusty plasma parameters.…”

Section: Discussionmentioning

confidence: 69%

“…Therefore, we find difficulty to use this new proposed technique to estimate the dust charge and electric field in the presence of external magnetic field. It has been noticed in earlier studies as well in present study that the electrostatic probes modify the dynamics of dust grains in a local region [5,53,54] and cannot be used to measure the plasma parameters and E-field during the wave motion. Since DAWs are excited due to adding more dust particles, plasma parameters without dust grains are not sufficient to explain the observed results.…”

Section: Discussionmentioning

confidence: 69%

See 1 more Smart Citation

Influence of external magnetic field on dust acoustic waves in a capacitive RF discharge

Choudhary

Bergert²,

Mitic³

et al. 2019

Contributions to Plasma Physics

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This paper reports experiments on self-excited dust acoustic waves (DAWs) andits propagation characteristics in a magnetized rf discharge plasma. The DAWs are spontaneously excited in dusty plasma after adding more particles in the confining potential well and found to propagate in the direction of streaming ions. The spontaneous excitation of such low-frequency modes is possible due to the instabilities associated with streaming ions through the dust grain medium. The background E-field and neutral pressure determine the stability of excited DAWs. The characteristics of DAWs strongly depend on the strength of external magnetic field. The magnetic field of strength B < 0.05 T only modifies the characteristics of propagating waves in dusty plasma at moderate power and pressure, P = 3.5 W and p = 27 Pa, respectively. It is found that DAWs start to be damped with increasing the magnetic field beyond B > 0.05 T and get completely damped at higher magnetic field B ∼ 0.13 T. After lowering the power and pressure to 3 W and 23 Pa respectively, the excited DAWs in the absence of B are slightly unstable. In this case, the magnetic field only stabilizes and modifies the propagation characteristics of DAWs while the strength of B is increased up to 0.1 T or even higher. The modification of the sheath electric field where particles are confined in the presence of the external magnetic field is the main cause of the modification and damping of the DAWs in a magnetized rf discharge plasma. K E Y W O R D Sdust acoustic wave, magnetized dusty plasma, magnetized plasma, RF discharge, superconducting magnet 1The presence of submicron to micrometre-sized particles in a plasma makes it more complex because these particles alter the dynamics of the plasma species (electrons and ions) as well as they exhibit their own dynamics. Such medium, which consists of three charged species namely electrons, ions, and charged solid particles, is termed as a dusty plasma or complex plasma. In the background of a low-temperature plasma, energetic electrons impinge on the surface of the solid particle and charge their surface negatively up to 10 3 -10 5 times of an electron charge [1] to balance the fluxes of electrons and ions. After the density of negatively charged dust particles crosses a critical value, then long-range coulombic interaction among the dust particles turnsThis is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

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Section: Discussionmentioning

confidence: 69%

Section: Discussionmentioning

confidence: 69%

Influence of external magnetic field on dust acoustic waves in a capacitive RF discharge

Choudhary

Bergert²,

Mitic³

et al. 2019

Contributions to Plasma Physics

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“…Note added.-After submission we became aware of a related investigation of probes in dusty plasmas [24].…”

mentioning

confidence: 98%

Dust-Free Regions around Langmuir Probes in Complex Plasmas under Microgravity

et al. 2004

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Dust-free regions around a Langmuir probe are studied in a complex plasma under microgravity. The dust particles settle in the presheath of the probe, where an equilibrium of the electric field force and the ion-drag force is established. The size and shape of the dust cloud are discussed with simple models. A more sophisticated presheath model is solved numerically to analyze the acting forces and the equilibrium position of the dust. The formation of distinct particle layers in the dust shell can be explained by the force gradients of the effective potential well.

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“…After inserting the probe in the discharge gap, a positive space-charge layer was formed around it. The same behavior of dust particles in the probe region in the glow discharge and in the radiofrequency discharge under microgravity conditions were described in [11][12][13][14]. Figure 6 shows the collecting surface of the probe and the area free from dust particles.…”

Section: Optical Diagnostics Of Dusty Plasmasmentioning

confidence: 58%

A Calculation of the Electron Temperature of Complex Plasma of Noble Gases Mixture in CCRF Discharge

Orazbayev

Ussenov

Рамазанов

et al. 2015

Contrib. Plasma Phys.

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In this paper the results of studying of the electron temperature of buffer and complex plasmas in mixtures of noble gases (helium + argon) in capacitively coupled radiofrequency (CCRF) discharge are presented. The optical properties of dusty plasma in argon, helium and their mixtures have been studied using optical diagnostic methods. Based on spectral lines of plasma forming gases, the dependence of the electron temperature on gas pressure and discharge power has been determined. The axial distribution of electron temperature in the interelectrode gap has been measured. Measurements have been made using an RF compensated electric probe. The comparison of the experimental results shows that admixture of a small amount of argon to helium leads to a decrease in the electron temperature of buffer plasma. The presence of dust particles in the plasma causes an increase in the electron temperature.

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Probe induced voids in a dusty plasma

Cited by 49 publications

References 17 publications

Influence of external magnetic field on dust acoustic waves in a capacitive RF discharge

Influence of external magnetic field on dust acoustic waves in a capacitive RF discharge

Dust-Free Regions around Langmuir Probes in Complex Plasmas under Microgravity

A Calculation of the Electron Temperature of Complex Plasma of Noble Gases Mixture in CCRF Discharge

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