Electrical conductivity of the thermal dusty plasma under the conditions of a hybrid plasma environment simulation facility

Abstract

We discuss the inductively heated plasma generator (IPG) facility in application to the generation of the thermal dusty plasma formed by the positively charged dust particles and the electrons emitted by them. We develop a theoretical model for the calculation of plasma electrical conductivity under typical conditions of the IPG. We show that the electrical conductivity of dusty plasma is defined by collisions with the neutral gas molecules and by the electron number density. The latter is calculated in the approximations of an ideal and strongly coupled particle system and in the regime of weak and strong screening of the particle charge. The maximum attainable electron number density and corresponding maximum plasma electrical conductivity prove to be independent of the particle emissivity. Analysis of available experiments is performed, in particular, of our recent experiment with plasma formed by the combustion products of a propane-air mixture and the CeO 2 particles injected into it. A good correlation between the theory and experimental data points to the adequacy of our approach. Our main conclusion is that a level of the electrical conductivity due to the thermal ionization of the dust particles is sufficiently high to compete with that of the potassium-doped plasmas. emission, photoemission, and thermionic emission [15-18]. It is possible in some cases for these emitted electrons to be major contributor to the electron density within the plasma, such as for UV-induced dusty plasmas [19,20], or in flames, where the thermionic emission from carbonaceous soot elevates the electron density by several orders of magnitude [21,22]. For a comprehensive discussion of these plasma types, see the review [23] and references therein. Recent studies based on the treatment of quantum states of the surplus electrons near the surface of charged particles make it possible to calculate such quantities as the electron sticking coefficient and desorption time, to account for the infrared extinction of dielectric particles etc [24][25][26][27].The characteristics of such complex plasmas have implications for applications as disparate as understanding volcanic eruptions, the explosiveness of dust clouds and powders, communications, wildfires, rocket propulsion, and fusion energy. Lightning associated with volcanic plumes is a direct result of the electrification of the particulate matter within the plume. As these particles are transported over large distances, the electric potentials which develop lead to lightning discharges. The electrical activity of volcanic eruptions is a possible method to monitor volcanic activity, both here on earth and on exoplanets [28]. Many industries handle large amount of powders such as paint, chemical fertilizer, grain powder, starch, detergent. As airborne dust particles become charged, a spark introduced into the system can ignite an explosion [29]. Care must be taken during transport to mitigate the effects, which can lead to accidental dust explosions [30]. Wildfires are weakly ionized ga...

Strongly Emitting Surfaces Unable to Float below Plasma Potential

“…However we note that our study only directly applies to thin (planar geometry) sheaths. Future studies can explore possible connections to curved emitting objects like dust grains in the fundamentally different orbital motion limited [31] and weakly screened [32] cases. Interestingly, potential wells have been observed around strongly emitting, positively charged dust grains in OML regime simulations without collisions [33].…”

Dust acoustic waves in three-dimensional complex plasmas with a similarity property

“…Since the mobility of electrons is much greater than that of ions, particles acquire a significant negative electric charge. This leads to formation of a strongly coupled plasma [1][2][3][4][5][6][7][8][9], in which various collective phenomena at the level of individual particles can be observed. Complex plasmas are studied in gas discharges at low pressures, e.g., in radio frequency (RF) discharges.…”

The IPG6-B as a research facility to support future development of electric propulsion

“…Over the past several years, the 6th generation inductively-heated plasma generator at Baylor University (IPG6-B) has been established as a research facility for application across numerous fields [1][2][3]. These include fundamental physics research in the field of (aerospace) engineering, astrophysics, geophysics and complex (dusty) plasma physics.…”