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Feldstärke, Stromdichten und mittlere Energien im Katodenfallraum von Glimmentladungen
Author(s) -
Hantzsche E.
Publication year - 1969
Publication title -
beiträge aus der plasmaphysik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.531
H-Index - 47
eISSN - 1521-3986
pISSN - 0005-8025
DOI - 10.1002/ctpp.19690090602
Subject(s) - atomic physics , torr , cathode , space charge , ion , chemistry , electron , range (aeronautics) , glow discharge , physics , materials science , plasma , nuclear physics , organic chemistry , composite material , thermodynamics
By integration of energy distribution functions for the cathode fall of H 2 glow discharges we may show: 1) Space charge is almost constant within a large part of the dark space, therefore the field strength is a nearly linearly decreasing function of distance from cathode. Deviations from linearity are quantitatively discussed. 2) Composition of space charge: The contribution of atomic ions to the space charge may range from 5 to 10%. and the contribution of electrons from 0,1 to 10%, increasing with growing voltage. 3) Relative ion and neutral current densities at the cathode (ion current from the glow edge = 1) are decreasing with growing voltage. Molecular neutral current density equals 3 to 10 times molecular ion current density, in case of atomic particles the relation is from 1 to 5. 4) Total current density is increasing from 2.0 · 10 −4 A/cm 2 torr 2 at the voltage U 0 = 0,19 kV to 3,7 A/cm 2 torr 2 at U 0 = 10 kV; cathode field strength is increasing from 0,53 kV/cm torr to 97 kV/cm torr. 5) The mean energy of neutrals is smaller than the mean ion energy by a factor of about 0.45…0.85, and the mean energy of molecules is smaller than the energy of atoms by a about 0.2…0.8. The dependence of the mean energies from voltage is discussed. 6) The energy gain of electrons is growing from 15% of total dark space energy at 0.19 kV to 70% at 10 kV; the energy gain of neutrals is decreasing at the same time.