Advances in non-equilibrium $$\hbox {CO}_2$$ plasma kinetics: a theoretical and experimental review

Abstract

Numerous applications have required the study of CO2 plasmas since the 1960s, from CO2 lasers to spacecraft heat shields. However, in recent years, intense research activities on the subject have restarted because of environmental problems associated with CO2 emissions. The present review provides a synthesis of the current state of knowledge on the physical chemistry of cold CO2 plasmas. In particular, the different modeling approaches implemented to address specific aspects of CO2 plasmas are presented. Throughout the paper, the importance of conducting joint experimental, theoretical and modeling studies to elucidate the complex couplings at play in CO2 plasmas is emphasized. Therefore, the experimental data that are likely to bring relevant constraints to the different modeling approaches are first reviewed. Second, the calculation of some key elementary processes obtained with semi-empirical, classical and quantum methods is presented. In order to describe the electron kinetics, the latest coherent sets of cross section satisfying the constraints of "electron swarm" analyses are introduced, and the need for self-consistent calculations for determining accurate electron energy distribution function (EEDF) is evidenced. The main findings of the latest zero-dimensional (0D) global models about the complex chemistry of CO2 and its dissociation products in different plasma discharges are then given, and full state-to-state (STS) models of only the vibrational-dissociation kinetics developed for studies of spacecraft shields are described. Finally, two important points for all applications using CO2 containing plasma are discussed: the role of surfaces in contact with the plasma, and the need for 2D/3D models to capture the main features of complex reactor geometries including effects induced by fluid dynamics on the plasma properties. In addition to bringing together the latest advances in the description of CO2 non-equilibrium plasmas, the results presented here also highlight the fundamental data that are still missing and the possible routes that still need to be investigated.

Electron and Positron Scattering Cross Sections from CO2: A Comparative Study over a Broad Energy Range (0.1–5000 eV)

“…This is mainly for atomic and molecular gases, − but an extension to liquids has recently been examined . In the case of e-CO 2 scattering in the gas phase, there seem to be enough cross section data that such AI/AL approaches might be gainfully applied, complementing the extensive recent work of Guerra, Alves and co-workers on this gas (see the review), as well as other electron transport simulation procedures as such recently applied by Gracía-Abenza et al to water vapor.…”

Fast gas heating and kinetics of electronically excited states in a nanosecond capillary discharge in CO2

“…Detailed zero-dimensional kinetic models are described in [14][15][16][17]. A recent review [18] demonstrating the state-of-the-art of theoretical, modeling and experimental aspects of plasma assisted conversion has been released by a collaboration of several European scientific groups.…”

Total Cross Sections for Electron and Positron Scattering on Molecules: In Search of the Dispersion Relation

“…CH 4 acts as an intrinsic cooler in carbon-lined tokamaks like JET, thanks to its high cross sections for the vibrational excitations in the region of a few eV, see reference [7]. Resonant processes in electron scattering in N 2 and CO 2 at a few eV (2.1 and 3.9 eV, respectively), enhancing the vibrational and rotational transitions, are the basis of high-power IR lasers [8]. For thermonuclear plasmas, the energy range up to 1 keV is of interest [9].…”