0474532 - ÚFCH JH 2018 RIV DE eng J - Journal Article
Annušová, A. - Čermák, P. - Rakovský, Jozef - Martišovitš, V. - Veis, P.
Monitoring active species in an atmospheric pressure dielectric-barrier discharge: Observation of the Herman-infrared system.
Contributions to Plasma Physics. Roč. 57, č. 2 (2017), s. 67-75. ISSN 0863-1042. E-ISSN 1521-3986
Institutional support: RVO:61388955
Keywords : dielectric-barrier discharge * Herman-infrared system * nitrogen
OECD category: Physical chemistry
Impact factor: 1.318, year: 2017

An electronic and spectroscopic study of dielectric-barrier discharge transition from the Townsend to the filamentary mode is presented. The discharge is generated under pure nitrogen flow at atmospheric pressure in a reactor with parallel configuration of cylindrical electrodes covered with Al2O3 dielectrics, applying a frequency of 4.85 kHz. The goal of the study was to find optimal conditions for observation of the Herman-infrared (HIR) transition (C ''(5)Pi(+)(u)Sigma(+)(g)) in a perspective to develop and test a ro-vibrational model for this quintet band. We have focused on finding the maximum emissivity of the HIR transition in the homogeneous discharge regime as it offers a more suitable source for calibrating the HIR model. Besides the capability of generating a spatially homogeneous type of radiation, our discharge design also allowed the observation of HIR without detectable interference from the first positive system of nitrogen which is not common for atmospheric pressure discharges. In the study, a time-resolved observation of the NO gamma system, the second positive and the HIR nitrogen systems were performed and their emissivities analysed as a function of the discharge period and power. The optimum for the observation of the HIR system was found at 2.94 W (power density of 6 W/cm(3)), corresponding to the Townsend discharge just before its transition to the filamentary one.
Permanent Link: http://hdl.handle.net/11104/0271569