Positive column of the Cs–Ar low‐pressure discharge

1974 ◽  
Vol 45 (1) ◽  
pp. 89-96 ◽  
Author(s):  
H. van Tongeren
Keyword(s):  
Positive Column ◽  
Low Pressure ◽  
Pressure Discharge

Modeling the Hg-Ar low-pressure-discharge positive column: A comparative study

1992 ◽  
Vol 45 (2) ◽  
pp. 1135-1148 ◽  
Author(s):  
G. Zissis ◽  
P. Bénétruy ◽  
I. Bernat
Keyword(s):  
Comparative Study ◽  
Positive Column ◽  
Low Pressure ◽  
Pressure Discharge

Asymptotic matching of plasma and sheath in an active low pressure discharge

1970 ◽  
Vol 4 (2) ◽  
pp. 371-385 ◽  
Author(s):  
R. N. Franklin ◽  
J. R. Ockendon
Keyword(s):  
Charged Particle ◽  
Balance Equation ◽  
Positive Column ◽  
Fluid Model ◽  
Fluid Velocity ◽  
Free Fall ◽  
Low Pressure ◽  
Pressure Discharge ◽  
Direct Numerical Integration ◽  
Asymptotic Matching

The method of matched asymptotic expansions is applied to the fluid model of the low-pressure positive column. The expansion of the eigenvalue in the plasma balance equation is obtained to second order in plane and in cylindrical geometry, and uniformly valid expressions for charged particle densities and fluid velocity in two separate regions are indicated.The free-fall model is also examined and the scales of the transition layer and sheath layer found. Comparison is made with the results of direct numerical integration of the equations involved for both models.

Massenspektrometrische Analyse der Hg2+ -Bildung in der positiven Säule der Hg-Ar-Niederdruckentladung / Mass-spectrometric Analysis of Hg2+ Formation in the Positive Column of the Mercury-Argon Low Pressure Discharge

1972 ◽  
Vol 27 (8-9) ◽  
pp. 1278-1286 ◽  
Author(s):  
G. Franck ◽  
H. Lüdemann
Keyword(s):  
Mass Spectrometer ◽  
Discharge Current ◽  
Positive Column ◽  
Low Pressure ◽  
Mass Spectrometric ◽  
Spectrometric Analysis ◽  
Mercury Vapour ◽  
Balance Equations ◽  
Current Ratio ◽  
Pressure Discharge

The ions effusing ambipolar out of the positive column of a mercury-argon low pressure dis­charge are analyzed in a quadrupol mass spectrometer. Besides the Hg+-ion we find the Hg2+-ion molecule. The measured current ratio i(Hg2+)/i(Hg+) in the mass spectrometer is proportional to the mercury vapour pressure pHg in the discharge. i(Hg2+)/i(Hg+) lies between 10-2 at pHg = 10-3 Torr and 1 at pHg = 0.1 Torr. - At constant argon- and mercury pressures i(Hg2+)/i(Hg+) is inversely proportional to the discharge current. - At constant discharge current and mercury vapour pressures the ratio i(Hg2+)/i(Hg+) is nearly independent of the argon pressure.An analysis of our measurements with the help of balance equations for excited Hg-atoms in the resonance level (3P1) and in the metastable 3P0 and 3P2 levels is carried out. It turns out that the only relevant process leading to the Hg2+*ion molecule is the reactionHg*+ Hg*→ Hg2++eof Hg-atoms in the levels 3P0, 3P1 and 3P2. It can be shown that the Hornbeck-Molnar-process Hg**+Hg → Hg2++e and the reactions Hg++2Hg→Hg2++ Hg, Hg++Hg+Ar→Hg2++Ar play an unimportant role in the Hg2+-ion formation.

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