scholarly journals Generation of plasma in low-pressure discharge

2021 ◽  
Vol 2064 (1) ◽  
pp. 012040
Author(s):  
S P Nikulin
Keyword(s):  
Hydrodynamic Model ◽  
Low Pressure ◽  
Critical Value ◽  
Plasma Potential ◽  
Anode Potential ◽  
Pressure Discharge ◽  
Ionization Frequency ◽  
Primary Electrons

Abstract A hydrodynamic model of plasma has been developed, which takes into account both secondary and primary electrons. It has been shown that a solution with a plasma potential higher than the anode potential is possible if the ionization frequency is higher than some critical value. At lower ionization frequencies, it is possible to obtain a solution with a plasma potential below the anode potential

Primary Electrons in a Low Pressure Discharge

1973 ◽  
Vol 485 (3-4) ◽  
pp. 185-205 ◽  
Author(s):  
H. Amemiya ◽  
K. Wiesemann
Keyword(s):  
Low Pressure ◽  
Pressure Discharge ◽  
Primary Electrons

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

scholarly journals A Subglacial Boundary-layer Regelation Mechanism

1990 ◽  
Vol 36 (124) ◽  
pp. 263-268 ◽  
Author(s):  
E.M. Shoemaker
Keyword(s):  
Boundary Layer ◽  
Heat Input ◽  
High Water ◽  
Low Pressure ◽  
Critical Value ◽  
High Water Content ◽  
Overburden Pressure ◽  
Basal Ice ◽  
The Difference ◽  
Linear Nature

AbstractHeat input to basal ice at subglacial low-pressure regions, such as exist on the lee side of bed bumps including regions of ice-bed separation, is shown to melt basal ice internally in a narrow boundary layer at most centimeters thick. Before ice at the ice-bed interface can begin to melt, the heat input Q must exceed a critical value Q*. Q* increases rapidly with an increase in the difference ΔΡ between the nominal (global) overburden pressure and the magnitude of the (local) normal stress acting between the ice and bed or ice and water pocket. Because of the non-linear nature of the flow law, the thickness of the boundary layer decreases rapidly with increasing ΔΡ. The ice in the boundary layer is likely to be soft with a high water content. Under certain conditions, a regelation cycle may exist between the boundary layer and the water in a subglacial cavity. The boundary layer is sufficiently narrow that the processes can reach steady state while ice traverses subglacial low-pressure regions of length the order of 0.01–0.1 m. The regelation phenomenon may preserve or aid the formation of narrow debris-rich ice layers at the base of temperate glaciers.

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