Numerical investigation of self-organization and stable burning conditions of moderate pressure glow discharges in argon gas

Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Edebiyat Fakültesi, Fizik Bölümü, Türkiye

Tezin Onay Tarihi: 2011

Öğrenci: ENDER EYLENCEOĞLU

Danışman: İSMAİL RAFATOV

Özet:

In this study numerical modelling of a moderate pressure DC glow discharge plasma is car- ried out in 1D and 2D geometry. The governing equations include continuity equations for the plasma species (electrons, positive ions and metastable atoms), the electron energy equation (EEE), Poisson equation for the electric ﬁeld in the discharge volume and the surface charge equation on the dielectric side walls. The electron transport coeﬃcients such as the electron diﬀusion and mobility as well as the electron-impact reaction rates for excitation, ionization and momentum transfer are obtained from look-up tables (LUT). The data in LUTs is tabu- lated as functions of mean electron energy and obtained from the solution of local Boltzmann equation. Calculations are carried out for the argon gas at 1 and 3 Torr pressures, using COM- SOL Multiphysics package. Investigated regimes include subnormal, normal and abnormal glow discharge modes. Current-voltage curves (CVC) and proﬁles for plasma parameters for the 1 and 3 Torr discharges are developed. Comparison of discharge plasma properties in 1D and 2D, as well as comparison with the available numerical data is performed.