Aachen PK 2003 – wissenschaftliches Programm

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P: Plasmaphysik

P 4: Poster I

P 4.26: Poster

Montag, 17. März 2003, 17:45–19:15, Foyer

Time resolved determination of the electron temperature in a Pseudospark discharge copper vapour plasma — •Jürgen Urban and Klaus Frank — Physikalisches Institut I, Universität Erlangen-Nbg., Erwin-Rommel-Str. 1, 91058 Erlangen, Germany

The Pseudospark discharge is a pulsed high current low pressure gas discharge which is located at the left branch of the so called Paschen curve. It operates in a special hollow cathode geometry with small boreholes connecting the main electrodes and the hollow electrodes. During the discharge formation process within the copper cathode borehole appears a transient dense glow discharge with an increasing appearance of copper vapour.

For the understanding of the role of this localised and at the inner rim homogeneously distributed copper vapour plasma time resolved emission spectroscopy was used to determine the electron density and the electron temperature as well. The copper vapour plasma was not in thermodynamic equilibrium at all. Therefore especially for the determination of the electron temperature from ionic to atomic line ratios the the exact equilibrium and non equilibrium processes have to be considered. It was possible to correct the measured results of the non equilibrium plasma to determine values of electron temperature. The measured electron densities rise with rising discharge currents from 1e14 to 1e16 cm-3, and the temperatures were calculated during the same periode in a decreasing range of 3 to 1 eV.