Bremen 2017 – wissenschaftliches Programm
P 23.15: Poster
Mittwoch, 15. März 2017, 16:30–18:30, HS Foyer
Phase resolved laser absorption spectroscopy on a low pressure dielectric barrier discharge jet — •Roman Bergert and Slobodan Mitic — I. Physikalisches Institut, Justust-Liebig Universität Gießen
Dielectric barrier discharge (DBD) jets at low pressures (≈ 100 Pa) were investigated by laser absorption targeting the 1s4 argon resonant state at 842.46 nm and fluorescence spectroscopy. The accuracy of the measurements was improved by synchronization of the laser scan with the voltage dynamics providing the possibility for phase resolved reconstruction of the measured absorption profiles.
Preliminary fits with a Gaussian profile resulted in pure description of measured profiles; wings indicating additional broadening components. The latter is considered to be caused by charge particles (Stark broadening) while pressure broadening at the applied pressures should not be detectable.
The laser absorption was measured across the jet, between electrodes, providing the phase resolved local information on the state density, gas temperature and electron density. Laser absorption in axial direction was also performed confirming strong phase dependent gas thermodynamics based on detection of Doppler shift induced florescence imaging of the plasma jet. The observed DBD jets had very strong phase dependent development with high densities and relatively low gas temperature making it a quite efficient and robust plasma source.