München 2019 – wissenschaftliches Programm

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P: Fachverband Plasmaphysik

P 6: Low Pressure Plasmas I

P 6.6: Vortrag

Montag, 18. März 2019, 18:00–18:15, HS 20

Phase resolved optical properties of magnetized transient plasma created by a low-pressure dielectric barrier discharge jet — •Roman Bergert and Slobodan Mitic — Justus-Liebig-Universität Gießen

Dielectric barrier discharge (DBD) jet with the influence of an ex- ternal constant magnetic field (0.3 T) at low pressure (100 Pa) were investigated by tuneable diode laser absorption spectroscopy in per- pendicular observation to the magnetic field. With this configuration each π and σ polarized transitions of Argon 1s at 842.47 nm and 1s at 801.48 nm were phase resolved by using unpolarized laser light. The changes within a discharge cycle for each polarization transition and sublevel density were observed to investigate the transient plasma during different regimes. To increase accuracy of our model, we calcu- late the individual Einstein coefficient for spontaneous decay between magnetic sublevel transitions. This enabled us to observe a significant change in the optical properties of transient plasma with an external magnetic field. This results in a changed average selfabsorption coef- ficient by almost 0.5 compared to an unsplitted case with same total 1s densities. This shows that the plasma becomes more transparent under the influence of an external magnetic field. The individual tran- sition properties are necessary for a correct description of the plasma emission and absorption with an external magnetic field.