Electric field determination in air plasmas from intensity ratio of nitrogen spectral bands: II. Reduction of the uncertainty and state-of-the-art model

Bı́lek, Petr; Obrusník, Adam; Hoder, Tomáš; Šimek, Milan; Bonaventura, Zdeněk

doi:10.1088/1361-6595/aad666

Cited by 39 publications

(51 citation statements)

References 114 publications

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“…Due to atmospheric pressure the effective lifetimes of the states in dry air are orders of magnitude lower than their radiative lifetimes, namely about 0.6 ns (N 2 (C 3 Π u ) state) and 0.05 ns (N 2 + (B 2 Σ u + ) state). 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.…”

Section: Experimental Set-upmentioning

confidence: 99%

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

Brandenburg

Jahanbakhsh

Schiorlin

et al. 2019

Plasma Chem Plasma Process

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The development of microdischarges and the inception dynamics of subsequent microdischarges in an electrode arrangement consisting of a metal pin and a hemispherical dielectric-covered electrode, operated in air with a small toluene admixture, is studied. The discharge is operated with sinusoidal high voltage. A gated ICCD camera and a current probe enable the recording of images and current pulses of the single microdischarges, respectively, while the spatio-temporally resolved development is measured with a multidimensional time-correlated single photon counting technique. The overall discharge dynamics changes significantly if a concentration of 35 ppm toluene is added to dry air. A lower high voltage amplitude than in dry air is needed for stable discharge operation. This can be explained by the lower ionization energy of toluene compared to molecular oxygen and nitrogen. The microdischarge development is the same with or without admixture, i.e. a positive (cathode directed) streamer mechanism is observed. Lower mean power is dissipated into the discharge when toluene is admixed. The main effect caused by toluene admixture is the suppression of high-energy microdischarges in case of the cathodic pin half-cycle of the sinusoidal high voltage. The influence on the inception voltage by additional ionization mechanisms and volume memory effects, the consumption of energetic electrons for toluene decomposition reactions, and the modification of the surface by plasma treatment are discussed as possible reasons.

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Section: Experimental Set-upmentioning

confidence: 99%

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

Brandenburg

Jahanbakhsh

Schiorlin

et al. 2019

Plasma Chem Plasma Process

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“…Despite the improvements, optical diagnostic methods of air discharges from the ratio of FNS to SPS at atmospheric pressure are still very sensitive to the considered chemical reactions rates (Obrusnik et al, ; Bílek et al, ). As Obrusnik et al () and Bílek et al () concluded, more efforts are needed for a more precise determination of the reaction rates (especially quenching rates) that are important for diagnostic methods based on the FNS emission at atmospheric pressure.…”

Section: Discussionmentioning

confidence: 99%

“…In Figure , we plot the peak electric field dependence of the emission ratios FNS

_{false(0, v^{''} false)}

/SPS and FPS/SPS using the described methods and the reaction rate coefficients of Table . We have also calculated the peak electric field dependence of the emission ratio FNS

_{false(0, v^{''} false)}

/SPS using the lowest and highest quenching rates of

{normalN}_{normal2}^{+}

^{2} {normal∑}_{u}^{+}

) by air provided by Bílek et al (). Comparison between the averaged uncertainty due to the quenching rates (40%) and the spatial nonuniformity (45%) in Figure shows that the effect of the spatial nonuniformity of the discharge in the estimation of the peak electric field from the FNS

_{false(0, v^{''} false)}

to SPS ratio is of the same order to that of quenching.…”

Section: Comparison Of Methods and Discussionmentioning

confidence: 99%

“…Finally, the term R ( t ) includes the remaining loss processes, such as intersystem processes or vibrational redistribution. Obrusnik et al () and Bílek et al () demonstrated that the most important processes that influence the optical emissions are the excitation of emitting molecules by electron impact, radiative de‐excitations, and electronic quenching. Therefore, we can neglect the effect of other processes in the derivation of the peak reduced electric field and approximate equation as

S false(t false) ≃ \frac{d N_{s} false(t false)}{d t} + A N_{s} false(t false) + Q N_{s} false(t false) N .

…”

Section: Spatial Nonuniformity Of the Electric Field In Spectroscopicmentioning

confidence: 99%

“…Apart from the spatial nonuniformity of the streamer discharge, the uncertainty of the reaction rates involved in the discharge can lead to a significant error in the estimated electric field (Creyghton, ; Hoder et al, ; Kozlov et al, ; Paris et al, ). Recently, Obrusnik et al () and Bílek et al () performed a sensitivity analysis to determine the effect of the reaction rate uncertainties in the obtained peak electric field at different pressures using the ratio of FNS to SPS. According to their results, the processes that significantly influence the error in the estimated peak electric field from optical emissions are the excitation by electron impact, the radiative de‐excitation, and the electronic quenching by air of electronically excited states of N 2 and

{normalN}_{normal2}^{+}

, especially at atmospheric pressure.…”

Section: Introductionmentioning

confidence: 99%

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Analysis of the Spatial Nonuniformity of the Electric Field in Spectroscopic Diagnostic Methods of Atmospheric Electricity Phenomena

et al. 2019

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The spatial non-uniformity of the electric field in air discharges, such as streamers, can influence the accuracy of spectroscopic diagnostic methods and hence the estimation of the peak electric field. In this work, we use a self-consistent streamer discharge model to investigate the spatial non-uniformity in streamer heads and streamer glows. We focus our analysis on air discharges at atmospheric pressure and at the low pressure of the mesosphere. This approach is useful to investigate the spatial non-uniformity of laboratory discharges as well as sprite streamers and blue jet streamers, two types of Transient Luminous Event (TLE) taking place above thunderclouds. This characterization of the spatial non-uniformity of the electric field in air discharges allows us to develop two different spectroscopic diagnostic methods to estimate the peak electric field in cold plasmas.The commonly employed method to derive the peak electric field in streamer heads underestimates the electric field by about 40-50 % as a consequence of the high spatial non-uniformity of the electric field. Our diagnostic methods reduce this underestimation to about 10-20%. However, our methods are less accurate than previous methods for streamer glows, where the electric field is uniformly distributed in space. Finally, we apply our diagnostic methods to the measured optical signals in the Second Positive System of N 2 and the First Negative System of N + 2 of sprites recorded by Armstrong et al. (1998) during the SPRITE's 95 and 96 campaigns.

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