Time-resolved study of the electron temperature and number density of argon metastable atoms in argon-based dielectric barrier discharges

Abstract

A combination of optical emission spectroscopy and collisional-radiative modelling is used to determine the time-resolved electron temperature (assuming Maxwellian electron energy distribution function) and number density of Ar 1s states in atmospheric pressure Ar-based dielectric barrier discharges in presence of either NH3 or ethyl lactate. In both cases, Te values were higher early in the discharge cycle (around 0.8 eV), decreased down to about 0.35 eV with the rise of the discharge current, and then remained fairly constant during discharge extinction. The opposite behaviour was observed for Ar 1s states, with cycle-averaged values in the 10 17 m −3 range. Based on these findings, a link was established between the discharge ionization kinetics (and thus the electron temperature) and the number density of Ar 1s state.

Influence of a square pulse voltage on argon-ethyl lactate discharges and their plasma-deposited coatings using time-resolved spectroscopy and surface characterization

“…Overall, in these conditions, Te and n(Arm) thus vary by compensating one another. A similar behavior was previously reported for helium DBDs [9,33] and argon-ammonia discharges [10,24]. Figure 5.…”

“…The most probable pair of electron temperature (Te) and number density of argon metastable atoms (n(Ar m )) was determined through a comparison between measured emission intensities from Ar 3p54p-to-3p54s transitions (2p-to-1s in Paschen notation) and those calculated using an argon collisional-radiative model described elsewhere [10,24].…”

“…The collisional-radiative model used in this work is based on a detailed analysis of 4p-to-4s argon transitions [10]. It considers electron-impact processes, excitation transfers, spontaneous emission, collision quenching, and radiation trapping effects [10,24]. The second part of the work focuses on correlating these discharge characteristics with the physicochemical properties of the plasmadeposited layers.…”

Electron characterization in weakly ionized collisional plasmas: from principles to techniques

“…One of the crucial pieces of information in this diagnostic method is the electron energy distribution function (EEDF). The Maxwellian distribution is reasonable and acceptable in discharges at atmospheric pressure [161,162], and it was used to determine the κ ea value in the earlier works. For distributions other than Maxwellian, the κ ea value should be carefully calculated with known EEDFs.…”

Optical Emission Spectroscopic (OES) analysis for diagnostics of electron density and temperature in non-equilibrium argon plasma based on collisional-radiative model

“…Even for the arc-discharge conditions, validity of the LTE condition is being examined in terms of the excitation population kinetics with the Ar-CR model [50]. Recently, the OES line-intensity measurement assisted with the CR model is being applied to understand the electron temperature of atmospheric-pressure discharge argon-based plasmas for various applications of material applications [51][52][53][54][55], energy applications [56][57][58], or aeronautical applications [59]. Of course, many reports are published relevant to the electron temperature measurement of argon-based lowpressure discharge plasmas by the OES measurement assisted with the CR model [60].…”