Self-consistent modelling of helium discharges: Investigation of the role of He2 + ions

Kinga Kutasi, Péter Hartmann, Zoltán Donkó

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

Helium glow discharges in the p = 6-60 mbar pressure range have been investigated experimentally and by means of a one-dimensional self-consistent hybrid model. Unlike most of the hybrid models developed previously for noble gas discharges, our model also includes He2 + molecular ions. The electrical parameters of the discharges, recorded in the experiments, as well as the electron temperature for the different discharge conditions (determined spectroscopically) have been used as input data for the hybrid model. Our studies show that He2 + ions are present in the discharge even at 6 mbar with a concentration comparable to that of He+ ions. Conversion of atomic to molecular ions and the associative ionization process are identified as main sources of molecular ions. At low pressures the He2 + ions are principally lost at the electrodes, while at higher pressures the recombination processes become their dominant losses. As the rates of recombination processes are strongly pressure-dependent, the optical emission spectrum changes with increasing pressure and shows significant intensity of He2 molecular bands. The contribution of He2 + ions to the ion current at the cathode as well as their contribution to maintenance of the discharge is found to be around 10%, even at the lowest pressure of 6 mbar, where He2 + formation in most of the discharge models is neglected.

Original languageEnglish
Pages (from-to)3368-3377
Number of pages10
JournalJournal of Physics D: Applied Physics
Volume34
Issue number23
DOIs
Publication statusPublished - Dec 7 2001

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Helium
helium
Ions
molecular ions
ions
low pressure
gas discharges
glow discharges
ion currents
maintenance
light emission
optical spectrum
rare gases
Noble Gases
emission spectra
cathodes
Electron temperature
electron energy
Glow discharges
Inert gases

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

Cite this

Self-consistent modelling of helium discharges : Investigation of the role of He2 + ions. / Kutasi, Kinga; Hartmann, Péter; Donkó, Zoltán.

In: Journal of Physics D: Applied Physics, Vol. 34, No. 23, 07.12.2001, p. 3368-3377.

Research output: Contribution to journalArticle

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