München 2019 – wissenschaftliches Programm
P 18.40: Poster
Donnerstag, 21. März 2019, 16:30–18:30, Foyer Audimax
Comparison of the OH A-X emission spectra for several different plasma sources — •Roland Friedl1, Caecilia Fröhler1, David Rauner1,2, Nicole Baar1, and Ursel Fantz1,2 — 1AG Experimentelle Plasmaphysik, Universität Augsburg, 86135 Augsburg — 2Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching
The resonant transition A→X of the hydroxyl molecule OH is studied in detail for several different discharges. Emission from an atmospheric glow discharge, an RF micro jet plasma, a microwave torch as well as a plasmoid are considered. For each discharge the OH molecule is generated from water vapor, which in turn is an impurity to the discharge, an intentional admixture to the discharge gas or even the main gaseous constituent. For comparison the spectrum of a low pressure ICP discharge in a gas mixture of 85 % H2 and 15 % O2 is studied. Analysis of the spectra is performed by using the LIFBASE Spectroscopy Tool (J. Luque and D. R. Crosley, SRI International, 1999). Depending on the specific discharge under observation, the spectral composition thus varies from nearly thermal equilibrium between vibrational and rotational states, via two-temperature rotational populations, through to spectra which are strongly affected by quenching processes. Furthermore, the influence of the spectral resolution on the accuracy of determined population temperatures and a comparison of the obtained rotational temperature to the gas temperature at the ICP is shown.
Acknowledgment: We thank RUB, CAU and IPP for providing spectra.