Düsseldorf 2007 – wissenschaftliches Programm
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P: Fachverband Plasmaphysik
P 21: Grundlegende Probleme, Theorie, Sonstiges
P 21.4: Vortrag
Donnerstag, 22. März 2007, 15:30–15:45, 6F
Analysis of long living plasmoid at atmospheric pressure — •Alex Versteegh1,2, Stefan Noack1, Burkhard Juettner1, and Gerd Fußmann1 — 1AG Plasmaphysik, Institut für Physik der Humboldt-Universität zu Berlin, Deutschland — 2Department of Applied Physics, Eindhoven University of Technology, Netherlands
Following preceding works of Russian groups free floating approximately spherical plasma clouds have been produced by capacitor discharges along a water surface at atmospheric pressure. Using a capacity of 1 mF and voltage of 4.8 kV these plasmoids have a diameter of 15 - 20 cm and radiate about 200 ms without external energy supply. The dynamics of the phenomenon are registered by a high speed camera. Using Langmuir probes the spatial distribution of charges and electric fields are measured. Highly resolved (λ/Δλ≈4·104), absolutely calibrated spectroscopic measurements are conducted in the wavelength range of 200–780 nm using an Echelle spectrometer. Several atomic and molecular particle species are identified. From probe and spectroscopic measurements estimates of plasma parameters (ne, Te) are deduced as a function of time. The investigations are aimed at understanding the energy storage mechanism that enables the autonomously radiating behavior. Explanations are sought for the characteristic spherical shape of the plasmoids and the observed appearance of radiating cylindrical “jets” extending vertically up to 50 cm above the discharge.