scholarly journals Ionization Balance in Low-Temperature Plasmas with Nanosized Dust

2021 ◽  
Vol 66 (4) ◽  
pp. 303
Author(s):  
V.I. Vishnyakov
Keyword(s):  
Low Temperature ◽  
Thermionic Emission ◽  
Dust Grains ◽  
Recombination Rates ◽  
Grain Number ◽  
Low Temperature Plasmas ◽  
Density Of Electrons ◽  
Ionization Balance ◽  
Dust Grain ◽  
Grain Surface

Ionization mechanisms in the low-temperature thermal plasma, which contains alkali metal atoms as ionizable component and nanosized dust grains, are studied. In such a plasma, electrons are captured by dust grains, because the work function of grains depends on their sizes, and the electron adsorption rate is more than the thermionic emission rate for nanosized grains. Accordingly, an increase of the dust grain number leads to a decrease in the volume ionization and recombination rates, because they depend on the number density of electrons. At the same time, the role of surface processes in the plasma ionization balance is increased, because the total grain surface is increased. The approximate calculation techniques for low and high grain number densities are proposed. The criterions for approximate calculations are specified.

scholarly journals Chemical Kinetics Simulations of Ice Chemistry on Porous Versus Non-Porous Dust Grains

2021 ◽  
Vol 8 ◽  
Author(s):  
Drew A. Christianson ◽  
Robin T. Garrod
Keyword(s):  
Chemical Kinetics ◽  
Interstellar Dust ◽  
Three Dimensional ◽  
Binding Energies ◽  
Inert Gases ◽  
Chemical Effect ◽  
Dust Grains ◽  
Interstellar Clouds ◽  
Dust Grain ◽  
Grain Surface

The degree of porosity in interstellar dust-grain material is poorly defined, although recent work has suggested that the grains could be highly porous. Aside from influencing the optical properties of the dust, porosity has the potential to affect the chemistry occurring on dust-grain surfaces, via increased surface area, enhanced local binding energies, and the possibility of trapping of molecules within the pores as ice mantles build up on the grains. Through computational kinetics simulations, we investigate how interstellar grain-surface chemistry and ice composition are affected by the porosity of the underlying dust-grain material. Using a simple routine, idealized three-dimensional dust-grains are constructed, atom by atom, with varying degrees of porosity. Diffusive chemistry is then simulated on these surfaces using the off-lattice microscopic Monte Carlo chemical kinetics model, MIMICK, assuming physical conditions appropriate to dark interstellar clouds. On the porous grain surface, the build-up of ice mantles, mostly composed of water, leads to the covering over of the pores, leaving empty pockets. Once the pores are completely covered, the chemical and structural behavior is similar to non-porous grains of the same size. The most prominent chemical effect of the presence of grain porosity is the trapping of molecular hydrogen, formed on the grain surfaces, within the ices and voids inside the grain pores. Trapping of H2 in this way may indicate that other volatiles, such as inert gases not included in these models, could be trapped within dust-grain porous structures when ices begin to form.

Low-temperature plasmas with nonequilibrium ionization

1979 ◽  
Vol 128 (6) ◽  
pp. 233 ◽  
Author(s):  
L.M. Biberman ◽  
V.S. Vorob'ev ◽  
I.T. Yakubov
Keyword(s):  
Low Temperature ◽  
Nonequilibrium Ionization ◽  
Low Temperature Plasmas

Nanosecond Pulse Burst Ignition of Ethylene and Acetylene by Uniform Low-Temperature Plasmas

2008 ◽  
Author(s):  
Evgeny Mintusov ◽  
Inchul Choi ◽  
Walter Lempert ◽  
Igor Adamovich ◽  
M. Nishihara ◽  
...  
Keyword(s):  
Low Temperature ◽  
Nanosecond Pulse ◽  
Pulse Burst ◽  
Low Temperature Plasmas

Drift-dissipative instability of the electromagnetic convection mode in a low-temperature plasma

1992 ◽  
Vol 47 (3) ◽  
pp. 439-443 ◽  
Author(s):  
Hamid Saleem ◽  
M. Y. Yu
Keyword(s):  
Low Temperature ◽  
Collisional Plasma ◽  
Low Temperature Plasma ◽  
Temperature Plasma ◽  
Electromagnetic Effects ◽  
Dissipative Instability ◽  
Low Temperature Plasmas ◽  
The Relationship

The convection mode in a collisional plasma is investigated, with the inclusion of electromagnetic effects. It is shown that a dissipative instability can occur. The relationship to several well-known modes as well as applications to typical low-temperature plasmas are discussed.

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