Modeling and Comparative Analysis of Atmospheric Pressure Anodic Carbon Arc Discharge in Argon and Helium–Producing Carbon Nanostructures

Abstract

In this work, within the framework of a unified model for the discharge gap and electrodes, a comparative numerical analysis was carried out on the effect of evaporation of graphite anode material on the characteristics of the arc discharge in helium and argon. The effect of changing the plasma-forming ion, in which the ion of evaporated atomic carbon becomes the dominant ion, is demonstrated. For an arc discharge in helium, this effect is accompanied by a jump-like change in the dependence of the current density on voltage (CVC), and smoothly for a discharge in argon. With regard to the dynamics of the ignition of an arc discharge, it is shown that during the transition from glow discharge to arc in helium, the discharge parameters are also accompanied by an abrupt change, while in argon, this transition is smooth. This is due to the fact that the ionization potentials, as well as the ionization cross sections, differ significantly for helium and carbon, and are close in value for helium and argon. For various points on the CVC, the density distributions of the charged and neutral particles of an inert gas and evaporated gases are presented.

Research progress on numerical simulation of arc discharge plasma process

“…The distribution of carbon atoms, carbon molecules and their ions is given at different discharge current densities. Later, Saifutdinov and Timerkaev [62] investigated the effect of evaporation of graphite anode material on the characteristics of He and Ar plasma. The results exhibited that the voltage had a potential jump with the change of current density in He plasma, which corresponded to the change of arc discharge state, in which a change in the plasma-forming ion was observed.…”

Formation of Black Silicon in a Process of Plasma Etching with Passivation in a SF6/O2 Gas Mixture

“…The most interesting examples of self-formation of nanostructures are observed in plasma processes of various natures. For example, in arc discharges, it is possible to observe not only the formation of nanostructures but also phase transformations, such as their crystallization [ 19 , 20 , 21 ].…”

Fast, Efficient Tailoring Growth of Nanocrystalline Diamond Films by Fine-Tuning of Gas-Phase Composition Using Microwave Plasma Chemical Vapor Deposition

“…Recent breakthroughs on material science and nanotechnology such as “stretching diamond to the limit” [ 1 ] and the amazing resolution for the major fragile problem of ceramics made of covalent bonds as diamond through “phasing out fracture” [ 2 ] stimulate more efforts on the development and research of nanomaterials [ 3 , 4 ]. Among different types of carbon nanostructures [ 5 , 6 ], those produced by various plasma methods, such as graphene [ 6 ] and nanocrystalline diamond [ 7 , 8 ], have become the most attractive in recent years. The deposition and development of NCD (of grain sizes usually less than 100 nm) films by CVD methods [ 7 , 8 , 9 ] is still ongoing because NCD films not only show many characteristics of microcrystalline diamond (MCD, of typical grain sizes larger than 500 nm) films [ 9 ], which inherit major advantages of diamond (high hardness, high electron emission efficiency and exceptional chemical inertness [ 4 ]), but also exhibit high surface smoothness due to their small grain sizes that potentiate low friction coefficients [ 4 , 10 , 11 , 12 , 13 ].…”