Modeling electronegative plasma discharge
- Univ. of California, Berkley, CA (United States)
Macroscopic analytic models for a three-component electronegative gas discharge are developed. Assuming the negative ions to be in Boltzmann equilibrium, a positive ion ambipolar diffusion equation is derived. The discharge consists of an electronegative core and electropositive edges. The electron density in the core is nearly uniform, allowing a parabolic approximation to the plasma profile to be employed. The resulting equilibrium equations are solved analytically and matched to a constant mobility transport model of an electropositive edge plasma. The solutions are compared to a simulation of a parallel-plane r.f. driven oxygen plasma for p = 50 mTorr and n{sub eo}= 2.4 x 10{sup 15} m{sup -3}. The ratio {alpha}{sub o} of central negative ion density to electron density, and the electron temperature T{sub e}, found in the simulation, are in reasonable agreement with the values calculated from the model. The model is extended to: (1) low pressures, where a variable mobility model is used in the electropositive edge region; and (2) high {alpha}{sub o} in which the edge region disappears. The inclusion of a second positive ion species, which can be very important in describing electronegative discharges used for materials processing, is a possible extension of the model.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- OSTI ID:
- 175504
- Report Number(s):
- CONF-9505200-; ON: DE96000983; TRN: 96:003538
- Resource Relation:
- Journal Volume: 75; Journal Issue: 5; Conference: 13. symposium on energy engineering sciences, Argonne, IL (United States), 15-17 May 1995; Other Information: PBD: [1995]; Related Information: Is Part Of Thirteenth symposium on energy engineering sciences: Proceedings. Fluid/thermal processes, systems analysis and control; PB: 275 p.
- Country of Publication:
- United States
- Language:
- English
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