Dark phase effect in the evolution of the positive column of a glow discharge in nitrogen

Journal Article · Wed Jun 15 04:00:00 EDT 2011 · Plasma Physics Reports

DOI:https://doi.org/10.1134/S1063780X11050035· OSTI ID:22047521

Dyatko, N A ^[1]; Ionikh, Yu Z; Meshchanov, A V ^[2]; Napartovich, A P ^[1]; Shishpanov, A I ^[2]

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1. Troitsk Institute for Innovation and Fusion Research (Russian Federation)
2. St. Petersburg State University (Russian Federation)

The characteristics of the initial stage of the formation of the positive column of a glow discharge in nitrogen at reduced pressures are studied experimentally and numerically. A dip in the plasma emission intensity in the initial stage of the discharge (the so-called 'dark phase') is observed experimentally at the positive polarity of the high-voltage electrode (the cathode is grounded). The dark phase is preceded by an ionization wave (IW). When the anode is grounded, neither an IW nor a dip in the discharge emission intensity are observed. A theoretical model capable of describing the discharge development under the actual experimental conditions is constructed. It is shown that the dark phase effect may be caused by the high electron density (above the steady-state one) produced in the gas during the passage of the IW across the discharge gap. This mechanism of the dark phase formation differs from the mechanism proposed earlier to explain a similar effect in noble gases. Additional experiments carried out with pure argon, helium, and helium with a nitrogen admixture have shown that, in the case of a grounded cathode, gas breakdown is also accompanied by the passage of an IW, whereas in the case of a grounded anode, no IW is observed; however, the dark phase is present in both cases. It is shown using computer simulations that, in nitrogen (in contrast to noble gases), the mechanism resulting in the dark phase effect does not operate in the absence of an IW.

• OSTI ID: 22047521
• Journal Information: Plasma Physics Reports, Journal Name: Plasma Physics Reports Journal Issue: 6 Vol. 37; ISSN PPHREM; ISSN 1063-780X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ANODES
ARGON
CATHODES
COMPUTERIZED SIMULATION
ELECTRIC POTENTIAL
ELECTRON DENSITY
EMISSION
GLOW DISCHARGES
HELIUM
IONIZATION
NITROGEN
PLASMA
PLASMA PRODUCTION
PLASMA SIMULATION
POSITIVE COLUMN
STEADY-STATE CONDITIONS