The effects of traces of molecular gases (H2, N2& O2) in glow discharges in noble gases

Abstract A self-consistent hybrid model of standing and moving striations was developed for low-current DC discharges in noble gases. We introduced the concept of surface diffusion in phase space (r,u) (where u denotes the electron kinetic energy) described by a tensor diffusion in the nonlocal Fokker-Planck kinetic equation for electrons in the collisional plasma. Electrons diffuse along surfaces of constant total energy ε=u-eφ(r) between energy jumps in inelastic collisions with atoms. Numerical solutions of the 1d1u kinetic equation for electrons were obtained by two methods and coupled to ion transport and Poisson solver. We studied the dynamics of striation formation in Townsend and glow discharges in Argon gas at low discharge currents using a two-level excitation-ionization model and a “full-chemistry” model, which includes stepwise and Penning ionization. Standing striations appeared in Townsend and glow discharges at low currents, and moving striations were obtained for the discharge currents exceeding a critical value. These waves originate at the anode and propagate towards the cathode. We have seen two types of moving striations with the 2-level and full-chemistry models, which resemble the s and p striations previously observed in the experiments. Simulations indicate that processes in the anode region could control moving striations in the positive column plasma. The developed model helps clarify the nature of standing and moving striations in DC discharges of noble gases at low discharge currents and low gas pressures.

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DC normal glow discharges in atmospheric pressure atomic and molecular gases

Plasma Sources Science and Technology ◽

10.1088/0963-0252/17/2/025013 ◽

2008 ◽

Vol 17 (2) ◽

pp. 025013 ◽

Cited By ~ 133

Author(s):

David Staack ◽

Bakhtier Farouk ◽

Alexander Gutsol ◽

Alexander Fridman

Keyword(s):

Atmospheric Pressure ◽

Molecular Gases ◽

Glow Discharges

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Quenching Rates for Metastable Oxygen Atoms(5S0)

Zeitschrift für Naturforschung A ◽

10.1515/zna-1973-0533 ◽

1973 ◽

Vol 28 (5) ◽

pp. 725-729 ◽

Cited By ~ 1

Author(s):

E.-P. Roth ◽

D. Perner ◽

J. W. Dreyer

Keyword(s):

Oxygen Atom ◽

Cross Section ◽

Absorption Spectroscopy ◽

Cross Sections ◽

Rate Constants ◽

Noble Gases ◽

Rare Gas ◽

Quenching Rate ◽

Collision Efficiency ◽

Molecular Gases

Metastable O (3s 5S0) atoms were produced by rare gas sensitized decomposition of various oxygen containing compounds. The quenching rate constants of H2 , N2, O2 , NO, N2O, N2O4/NO2, CO, CO2, SO2 , SO3 , H2O and the noble gases for the 0 (5S) have been measured by absorption spectroscopy. The noble gases, except xenon, deactivate the metastable oxygen atom with low collision efficiency. Xenon and molecular gases, except hydrogen, deactivate this species efficiently, the cross section being of the order of gas kinetic cross sections.

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Non-Self-Sustained Glow Discharges in Atmospheric-Pressure Inert and Molecular Gases in a Three-Electrode Configuration

IEEE Transactions on Plasma Science ◽

10.1109/tps.2011.2157530 ◽

2011 ◽

Vol 39 (11) ◽

pp. 2098-2099 ◽

Cited By ~ 1

Author(s):

Yauhen A. Safronau ◽

Leanid V. Simonchik

Keyword(s):

Atmospheric Pressure ◽

Electrode Configuration ◽

Molecular Gases ◽

Glow Discharges

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Similarity Relations for Low Pressure Glow Discharges in Noble Gases

IEEE Transactions on Plasma Science ◽

10.1109/tps.1974.4316852 ◽

1974 ◽

Vol 2 (4) ◽

pp. 283-290 ◽

Cited By ~ 11

Author(s):

Richard W. Callis ◽

David T. Tuma

Keyword(s):

Noble Gases ◽

Low Pressure ◽

Similarity Relations ◽

Glow Discharges

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Enhancement of analyte atomic lines with excitation energies of about 5 eV in the presence of molecular gases in analytical glow discharges

Journal of Analytical Atomic Spectrometry ◽

10.1039/c4ja00193a ◽

2014 ◽

Vol 29 (11) ◽

pp. 2022-2026 ◽

Cited By ~ 7

Author(s):

Sohail Mushtaq ◽

Edward B. M. Steers ◽

Juliet C. Pickering ◽

Petr Šmid

Keyword(s):

Excitation Energies ◽

Molecular Gases ◽

Glow Discharges ◽

Atomic Lines

Small amounts of hydrogen or oxygen in either argon or neon plasmas cause previously unexplained enhanced excitation of various analyte atomic lines with upper energies close to 5 eV.

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