Mutual influence of higher diffusion and radiation modes on the contraction of the positive column discharge

• Published in: Plasma sources science & technology Vol. 26; no. 1; pp. 15012 - 15024
• Main Authors: Golubovskii, Yu B, Siasko, A V, Nekuchaev, V O
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.01.2017
• Subjects: contraction; DC column; radiation transport; resonance radiation
• ISSN: 0963-0252; 1361-6595; 1361-6595
• DOI: 10.1088/1361-6595/26/1/015012

Fourier analysis of various plasma components in contracted discharge is made by an expansion over diffusion and radiation modes. Resonance atoms transport is traditionally described by an approximation of the effective lifetime by Holstein which considers only a fundamental radiation mode. Proposed method makes it possible to estimate the role of resonance radiation transport quantitatively by comparing the mode spectra. Behavior of resonance atoms successively considered on simple three-level energy models in a linear Shottky theory and in a semi-analytical non-linear diffusion-recombination theory, describing a discharge contraction. Suggested Fourier analysis method has been applied to a detailed model of the DC column contraction in Argon glow discharge. An expansion of different plasma components (electron density, metastable and resonance atoms densities) over the corresponding orthonormal set of diffusion or radiation modes is performed. The comparison of spectra obtained using the traditional Holstein approximation and in case of accurate treatment of resonance radiation transport shows an increase of fundamental diffusion and radiation modes and an effect of higher harmonics suppression in the modes spectra when the resonance radiation transport is described precisely. The role of higher radiation modes in formation of radial profiles of the electron density, metastable and resonance atoms densities as well as current-voltage characteristics is demonstrated by specific examples.