Investigation of surface-wave sustained discharge in neon by optical emission spectroscopy and collisional-radiative modelling
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| Year of publication | 2013 |
| Type | Conference abstract |
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| Citation | |
| Description | The aim of this work is to extend a previously developed method of determination of an electron temperature from optical emission spectra to surface-wave sustained microwave discharges. A surface-wave sustained discharge in coaxial tube structure in neon at low pressure (300–700 Pa) was studied by an optical emission spectroscopy. The spectra of the discharge were analyzed first with self-absorption methods in order to determine the densities of neon metastable states 1s3 and 1s5. The optical spectra measured in absorption-free direction were then analyzed with a 0D collisional-radiative model for neon discharge in order to determine the electron temperature and the reduced electric field strength in the discharge. Two types of the electron distribution function were used in the calculations – the Maxwellian EDF and the solution of the Boltzmann kinetic equation. The neon metastable densities determined from the self-absorption method depended on the gas pressure ranging 0.10–0.46 x 1016 m-3 and 3.2–4.2 x 1016 m-3 for 1s3 and 1s5 state, respectively. The reduced electric field strength decreased with the pressure from 10.5 to 4.5 Td, influencing only little the mean electron energy of about 3.5 eV. At such electric field strengths, the electron distribution functions determined using the Boltzmann solver were apparently non-Maxwellian due to the inelastic electron collisions with the neutral gas. Assuming Maxwellian EDF, the electron temperature was decreasing in the range of 1.6–1.4 eV with the pressure. The axial profiles of the reduced electric field strength and the Maxwellian temperature were found practically constant. |
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