Berlin 2001 – scientific programme

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P: Plasmaphysik

P 9: Dense Plasmas and Plasma Diagnostic (Poster Session)

P 9.22: Poster

Tuesday, April 3, 2001, 12:30–15:00, AT2

Electron energy distribution functions in RF und ECR plasmas — •P. Starke, U. Fantz, T. Ondak, and K. Behringer — Lehrstuhl für Experimentelle Plasmaphysik, Institut für Physik, Universität Augsburg, 86135 Augsburg

The knowledge of electron energy distribution functions (EEDF) is of great importance for plasma modeling or interpretation of measurements. The EEDF was determined in RF and ECR discharges in different gases by a combination of calculations and diagnostics. The solution of the homogenous Boltzmann equation yields the EEDF whereas the electrical field strength was used in order to match the line radiation of various gases. In case of RF discharges Langmuir probe measurements were available, resulting an EEDF in the energy range between approximately 1 and 20 eV. Investigations were carried out in different argon and helium plasmas as well as mixtures of helium with hydrogen or deuterium. The pressure varies from 5 to 50 Pa in RF discharges and from 4 to 18 Pa in ECR discharges. Different argon and helium transitions were examined spectroscopically. When interpreting the radiation of the ECR plasma, the population of the metastable levels was taken into consideration, as it was determined by absorption measurements.The results of the RF and ECR plasmas will be compared.