1. Dynamics of Gas Heating in the Afterglow of Pulsed CO2 and CO 2-N2 Glow Discharges at Low Pressure
- Author
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Carlos D Pintassilgo, M. Grofulović, Tiago Silva, Vasco Guerra, Loann Terraz, and Faculdade de Engenharia
- Subjects
010302 applied physics ,Physical sciences, Technological sciences, Engineering and technology ,Materials science ,General Chemical Engineering ,Ciências Físicas, Ciências Tecnológicas, Ciências da engenharia e tecnologias ,Kinetics ,General Chemistry ,Gas heating ,Engineering and technology ,Condensed Matter Physics ,01 natural sciences ,010305 fluids & plasmas ,Surfaces, Coatings and Films ,Afterglow ,Thermal conductivity ,Volume (thermodynamics) ,Excited state ,0103 physical sciences ,Ciências da engenharia e tecnologias ,Fourier transform infrared spectroscopy ,Atomic physics ,Thermal balance - Abstract
The time-dependent evolution of the energy transfer into gas heating in the afterglow of pulsed CO2 and CO2–N2 glow discharges produced in cylindrical tubes at low pressures (1–5 Torr) is theoretically investigated, by developing a self-consistent model that couples the time-dependent gas thermal balance equation with the vibrational kinetics. The modelling predictions are in good agreement with recently published experimental data on gas temperature, obtained via time-resolved in situ Fourier transform infrared spectroscopy. The cooling of the gas in the afterglow is found to be strongly dependent on the thermal conductivity and the wall temperature. It is verified that wall and volume deactivation of CO2 vibrationally excited species influences the gas heating along the afterglow, in different proportions depending on the pressure of the gas. The time-resolved contributions of each of these cooling and heating mechanisms are discussed in detail. The new results bring an additional validation of a set of mechanisms and rate coefficients for vibrationally-energy transfers previously proposed.
- Published
- 2020