Kinetic simulation of discharges and afterglows in molecular gases

V. Guerra, K. Kutasi, M. Lino Da Silva, P. A. Sá, J. Loureiro

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

A detailed kinetic model is designed and developed in order to investigate gas discharges in molecular plasmas and their afterglows. The theoretical formulation comprises the description of the electron, vibrational, chemical, ionic and surface kinetics. The model is applied to study and interpret two rather different phenomena. The first one is the nitrogen pink afterglow. It is established that the maxima present in the concentrations of several species - which appear downstream from the discharge in a flowing nitrogen afterglow, in a field-free region and after a dark zone - are formed as a result of the V-V up-pumping of N2(1g) molecules, followed by V-E transfers producing locally the metastable states N2(3u) and N2(α,1-u). The need for an accurate description of the high vibrational levels is pointed out. The vibrational energy levels are recalculated from the RKR method and used additionally in the study of dissociation in extreme re-entry conditions. The second application is the study of a plasma sterilization system using an Ar-O2 mixture. It is shown that the Ar(4s) do not survive long enough to be responsible for the UV/VUV emissions in the reactor, and that O2 is strongly dissociated. Moreover, the choice of the wall material can contribute significantly to create a more homogeneous distribution of several active species.

Original languageEnglish
Pages (from-to)141-156
Number of pages16
JournalHigh Temperature Material Processes
Volume14
Issue number1-2
DOIs
Publication statusPublished - 2010

Keywords

  • Boltzman equation
  • Gas discharges
  • Kinetic model
  • Molecular gases
  • Nitrogen afterglow
  • Plasma
  • RKR (Rydberg-Klein-Rees) method

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Energy Engineering and Power Technology
  • Engineering(all)
  • Spectroscopy
  • Physical and Theoretical Chemistry

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