A simple collisional–radiative model for low-temperature argon discharges with pressure ranging from 1 Pa to atmospheric pressure: kinetics of Paschen 1s and 2p levels

Abstract

A simple collisional–radiative model for the Paschen 1s and 2p levels is proposed for low-temperature argon discharges. This model can predict the population distribution of 1s and 2p levels over a wide discharge pressure range 1–105 Pa and ionization ratio range 10−6–10−3. The modelling results are found to be in good agreement with observed optical emissions from several different types of argon discharges at 1, 100 and 105 Pa. By using the model, the dominant kinetic processes of 1s and 2p levels are investigated for an electron beam plasma, an inductively coupled plasma, a capacitively coupled plasma and a microwave microplasma. A kinetic diagram is given, which can be used to identify the kinetic state of 1s and 2p levels in many low-temperature argon discharges reported in the literature. This model is also useful for obtaining discharge parameters from optical emissions in low-temperature argon discharges.

Status and Prospects on Nonequilibrium Modeling of High Velocity Plasma Flow in an Arcjet Thruster

“…e þ Ar à ð12Þ Figure 5 compares electron temperature dependence of the reaction rate coefficients presented by different authors for the same process (12). Generally reasonable trend is found among the values of reaction rate coefficients presented by Zhu [40], Baeva [41], and Gudmundsson [42]. However, the reaction rate coefficients presented by different authors show increasing differences with increase of electron temperature, especially for the reaction rate coefficient given by Shon [43], which is two orders smaller than those from other authors.…”

Measurement of Reactive Hydroxyl Radical Species Inside the Biosolutions During Non-thermal Atmospheric Pressure Plasma Jet Bombardment onto the Solution

“…We have tried to apply the CR model for Ar plasma in contact with biological solution where there are very large amount of water vapor and the plasmaforming gas, since the excited 2p emission lines from Ar atoms are not changed by addition of water molecules and other plasma-forming gases. The electron temperature in Ar plasma in contact with biological solution could be measured accurately by our CR model, since the physical parameters of rate coefficients for Ar gas plasma have been well studied and established [13] for electron temperature measurements. We have also assumed that these physical parameters of rate coefficients for Ar gas at atmospheric pressure can be used even to the environments in contact with biological solutions.…”

“…Population of the 2p excited argon levels (2p 1 *2p 10 in Paschen notation) mainly occurs by electron collisions with argon atoms in the ground level and with atoms in the metastable levels (1s 3 and 1s 5 in Paschen notation) [11]. Here the excited Ar atoms to 2p levels from resonant states (1s 2 and 1s 4 ) and quenching effects caused by the excited atoms from higher 3p levels [13] have been neglected for analytical simplicity since most of emission intensities are caused by electron impact in this experiment. Therefore, the balance equation for a 2p x (Paschen notation) excited level can be written as,…”

Electron and ion kinetics in three-dimensional confined microwave-induced microplasmas at low gas pressures

“…Specifically, the division of excited levels, the selection of production and depopulation processes of excited levels, and the rate coefficient for each process, all influence the accuracy of determining n e and T e . Many reports have been published on topics related to this issue, including effective level division [24][25][26] and databases of cross-sections. 27 However, the rate coefficient calculation from the corresponding cross-section depends on the electron energy distribution function (EEDF).…”

“…The Maxwellian distribution cannot be satisfied for all microplasma sources, which leads to a complicated calculation. Zhu and Pu 25 proposed a kinetic diagram to identify kinetic states of 1s and 2p levels in many low-temperature argon discharges. However, for TDC microplasmas with dimensions of hundreds of micrometers and operating at low pressures, the kinetic diagram does not fit.…”