Comparison of simulations and experiments on the axial distributions of the electron density in a point-to-plane streamer discharge at atmospheric pressure

Abstract

The axial distributions of the electron density in primary streamer discharge for atmosphericpressure air are simulated and compared with experimental data obtained by Inada et al (2017 J. Phys. D: Appl. Phys. 50 174005) using a highly temporally and spatially resolved measurement method for Shack-Hartmann-type laser wavefront sensors. The simulation is performed for the same electrode configuration, applied voltage, and gas component as the previously reported experiments. The simulation results show that the dissociative recombination reaction of electrons with cluster ion has an important influence on the axial distributions of the electron density during the primary streamer phase. However, the simulation results also indicate that the effect of the dissociative recombination reaction with cluster ion is limited to the primary streamer phase and the two-body attachment reaction of the electrons with O 2 is dominant for the decrease in electron density occurring during the secondary streamer phase. These findings contribute to improving the accuracy of the chemical reaction model of atmospheric-pressure streamer discharge, facilitating the development of atmospheric-pressure plasma applications.

Two-dimensional electron density measurement of pulsed positive secondary streamer discharge in atmospheric-pressure air

“…However, these distributions had not been predicted in the previous simulation study [17]. Recently, such axially non-uniform electron density distributions have been demonstrated to be caused by recombinations between electrons and O + 4 [18]. In this manner, the 2D electron density distributions are useful for identifying the main production/consumption pathways of the radicals and electrons.…”

“…In E/N > 130 Td, the sum of the ionisation rates is higher than the sum of the attachment rates; therefore, the decaying time constant of the electron density τ d shows a negative value due to the negative k d . According to the calculation using Bolsig+, reactions (R1) and (R2) are the dominant production process of electrons in phase (i), where E/N > 130 Td, whereas in phase (iii), where E/N ∼ 95 Td, reaction (R4) is a more dominant electron loss process compared with recombination reactions such as e + N + 2 −→ 2N( 4 S), which can contribute to the electron consumption in the primary streamer channels [16,18].…”

“…The Talbot system was successfully used for the measurement of the 2D electron density distributions over the positive secondary streamer discharges propagating in a 13 mm-long air gap between a point anode and a plane cathode. Since the majority of simulation studies has been conducted for the positive streamers [17,18,[21][22][23], the positive polarity was selected in this study for comparison with the previously reported numerical analysis [17,18]. A decaying process of the electron density is also discussed based on the temporal dynamics of the electric fields in the secondary streamers.…”

Generation of the single-filament pulsed positive streamer discharge in atmospheric-pressure air and its comparison with two-dimensional simulation

“…The authors have developed a 2D simulation of pulsed positive streamer discharge. The streamer propagation, reactive species densities, and electron densities were simulated and compared with the measurement results to validate the simulation [2,6]. However, there was difficulty in performing the comparison because the streamer caused non-reproducible 3D branching, which limited the comparison of the 2D simulation with the measurement results.…”

Review of numerical simulation of atmospheric-pressure non-equilibrium plasmas: streamer discharges and glow discharges

“…In fact, in the primary streamer channel whose E/N is approximately 10-30 Td, 129,133) the electrons are rapidly decayed by + O 4 and water-moleculederived cluster ions (H 3 O + (H 2 O) 3 + e), while in the secondary streamer, the two-body attachment reaction is more dominant. 157,158) While it is difficult to predict the properties of a primary streamer from the effective attachment (or ionization) coefficients described above, it is easier to predict the field strength, distribution, and current decay rate of secondary streamers. Using the analytical models for secondary streamers developed by Marode, 120) Bastien, 131) and Sigmond, 1) it is possible to roughly estimate the radical formation in the streamer given the distribution of the electron density produced by the primary streamer and the E/N-dependent effective ionization coefficient and chemical reaction set.…”