Electric field determination in air plasmas from intensity ratio of nitrogen spectral bands: I. Sensitivity analysis and uncertainty quantification of dominant processes

Abstract

The ratio of the spectral band intensities of the first negative and second positive spectral systems of molecular nitrogen is a well recognized method for indirect determination of the electric field. It is applied for various plasmas, e.g. barrier and corona discharges for industrial applications or geophysical plasmas occurring in the Earth’s atmosphere. The method relies on the dependence of the intensity ratio R(E/N) of selected bands on the reduced electric field strength. Both experimental and theoretical approaches have been used to determine this dependence, yet there still is a rather large spread in the data available in literature. The primary aim of this work is to quantify the overall uncertainty of the theoretical R(E/N) dependence and identify the main sources of this uncertainty. As the first step we perform sensitivity analysis on a full N2/O2 plasma kinetics model to find a minimal set of processes that are influential for the R(E/N) dependence. It is found to be in agreement with simplified kinetic models generally used. Subsequently, we utilize Monte Carlo-based uncertainty quantification to provide a confidence band for the electric field obtained from the theoretical R(E/N) dependence. Finally, subsequent steps are proposed to significantly reduce the uncertainty of the method.

Surface Dielectric Barrier Discharge plasma: a suitable measure against fungal plant pathogens

“…4b). Using FNS/SPS calibration curves 62 we can estimate that the averaged reduced electric field E/N exceeds 900 Td. Figure 5 shows characteristics vibrational distributions of N 2 (C 3 ∏ u ) evaluated from time and space averaged spectra shown in Fig.…”

The Equivalent Circuit Approach for the Electrical Diagnostics of Dielectric Barrier Discharges: The Classical Theory and Recent Developments

“…For completeness, other approaches for electrical diagnostics of DBD should be mentioned: for example, statistical methods based on detailed analysis of the shapes of the current pulses measured in a DBD driven by sinusoidal voltage [24,26,27], modeling of the discharge processes [28][29][30], the simulation of the measured characteristics by defining the properties of lumped electrical elements of the equivalent circuit in XCOS/Scilab or the Simulink environment [31][32][33][34], or optical measurements of the electric field [35][36][37] and electron densities [38,39].…”

About the Development and Dynamics of Microdischarges in Toluene-Containing Air

“…A comprehensive overview about lifetimes and quenching coefficients for the calculation of effective lifetimes is given in [53]. A detailed sensitivity analysis including 617 elementary processes performed in [54] revealed that the above mentioned processes are the most dominant and sufficient to describe the radiation kinetics in weakly ionised atmospheric pressure plasmas in dry air. Due to the much higher excitation energy of N 2 + (B 2 Σ u + ) the FNS emission is an indicator the development of the electric field strength, while SPS emission is interpreted as a convolution of the electric field strength and the local electron density [31][32][33]54].…”

“…Obviously, the effective lifetime of the excited states is not influenced by the presence of toluene due to its low density compared to nitrogen and oxygen. The rate coefficients for the quenching of the state N 2 (C 3 Π u ) by nitrogen and oxygen are k C q,N2 = (0.4 − 1.7) × 10 −11 cm 3 ∕s and k C q,O2 = (1.9 − 3.3) × 10 −10 cm 3 ∕s , respectively [54]. For the state N 2 + (B 2 Σ u + ) these constants are k B q,N2 = (1.4 − 9.8) × 10 −10 cm 3 ∕s and k B q,O2 = (4.4 − 11.0) × 10 −10 cm 3 ∕s , respectively [54].…”

“…The rate coefficients for the quenching of the state N 2 (C 3 Π u ) by nitrogen and oxygen are k C q,N2 = (0.4 − 1.7) × 10 −11 cm 3 ∕s and k C q,O2 = (1.9 − 3.3) × 10 −10 cm 3 ∕s , respectively [54]. For the state N 2 + (B 2 Σ u + ) these constants are k B q,N2 = (1.4 − 9.8) × 10 −10 cm 3 ∕s and k B q,O2 = (4.4 − 11.0) × 10 −10 cm 3 ∕s , respectively [54]. Rate coefficients for the quenching of the states by toluene are not known, but should be in the order of 10 −4 cm 3 ∕s to have a significant influence on the effective lifetime under the conditions being considered.…”