scholarly journals The emission properties, structure and stability of ionic liquid menisci undergoing electrically assisted ion evaporation

2022 ◽  
Vol 933 ◽  
Author(s):  
Ximo Gallud ◽  
Paulo C. Lozano
Keyword(s):  
Ionic Liquid ◽  
Steady State ◽  
Ion Source ◽  
Emission Region ◽  
Tension Stress ◽  
Liquid Temperature ◽  
Axially Symmetric ◽  
Current Output ◽  
Hydraulic Impedance ◽  
Ion Evaporation

The properties and structure of electrically stressed ionic liquid menisci experiencing ion evaporation are simulated using an electrohydrodynamic model with field-enhanced thermionic emission in steady state for an axially symmetric geometry. Solutions are explored as a function of the external background field, meniscus dimension, hydraulic impedance and liquid temperature. Statically stable solutions for emitting menisci are found to be constrained to a set of conditions: a minimum hydraulic impedance, a maximum current output and a narrow range of background fields that maximizes at menisci sizes of 0.5–3 ${\rm \mu}{\rm m}$ in radius. Static stability is lost when the electric field adjacent to the electrode that holds the meniscus corresponds to an electric pressure that exceeds twice the surface tension stress of a sphere of the same size as the meniscus. Preliminary investigations suggest this limit to be universal, therefore, independent of most ionic liquid properties, reservoir pressure, hydraulic impedance or temperature and could explain the experimentally observed bifurcation of a steady ion source into two or more emission sites. Ohmic heating near the emission region increases the liquid temperature, which is found to be important to accurately describe stability boundaries. Temperature increase does not affect the current output when the hydraulic impedance is constant. This phenomenon is thought to be due to an improved interface charge relaxation enhanced by the higher electrical conductivity. Dissipated ohmic energy is mostly conducted to the electrode wall. The higher thermal diffusivity of the wall versus the liquid, allows the ion source to run in steady state without heating.

High‐intensity H− ion source with steady‐state plasma injection

1986 ◽  
Vol 57 (5) ◽  
pp. 827-830 ◽  
Author(s):  
A. I. Hershcovitch ◽  
V. J. Kovarik ◽  
K. Prelec
Keyword(s):  
Steady State ◽  
High Intensity ◽  
Ion Source ◽  
Plasma Injection ◽  
State Plasma

Steady-state operation of a large-area high-power RF ion source for the neutral beam injector

2014 ◽  
Vol 65 (8) ◽  
pp. 1273-1276 ◽  
Author(s):  
Doo-Hee Chang ◽  
Min Park ◽  
Seung Ho Jeong ◽  
Tae-Seong Kim ◽  
Kwang Won Lee ◽  
...  
Keyword(s):  
Steady State ◽  
High Power ◽  
Ion Source ◽  
Neutral Beam ◽  
Large Area ◽  
Neutral Beam Injector ◽  
Steady State Operation ◽  
Rf Ion Source

Skilled-Unskilled Wage Inequality, Growth of Skilled Labour and Development Policies

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Manash Ranjan Gupta ◽  
Priya Brata Dutta
Keyword(s):  
Steady State ◽  
Wage Inequality ◽  
Open Economy ◽  
Relative Wage ◽  
Agricultural Product ◽  
Skilled Workers ◽  
Current Output ◽  
Skilled Labour ◽  
Traded Goods ◽  
Unskilled Labour

AbstractThis paper develops a small open economy model with three sectors and four factors – land, unskilled labour, skilled labour and capital. Two of these three sectors produce final traded goods of which one sector produces an agricultural product using land and unskilled labour and another sector produces a manufacturing product using skilled labour and capital. The third sector, called education sector produces a service using skilled labour and capital as inputs; and this service transforms unskilled workers into skilled workers. The current output is added to the existing stock of skilled labour at the next point of time. The paper first analyses various comparative static effects on skilled-unskilled relative wage in the static model where no factor endowment changes over time. Next, it analyses the long-run equilibrium properties in the dynamic model with intertemporal accumulation of skilled labour; and derives various comparative steady state effects on skilled unskilled relative wage. Comparative steady-state effects appear to be stronger than the corresponding comparative static effects.

scholarly journals Emission Modes in Electrospray Thrusters Operating with High Conductivity Ionic Liquids

Aerospace ◽  
2020 ◽  
Vol 7 (10) ◽  
pp. 141
Author(s):  
Nolan M. Uchizono ◽  
Adam L. Collins ◽  
Anirudh Thuppul ◽  
Peter L. Wright ◽  
Daniel Q. Eckhardt ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Steady State ◽  
High Speed ◽  
Liquid Propellant ◽  
Long Distance ◽  
Flow Rates ◽  
Extraction Voltage ◽  
Wide Range ◽  
Emission Behavior ◽  
Definition Of

Electrospray thruster life and mission performance are strongly influenced by grid impingement, the extent of which can be correlated with emission modes that occur at steady-state extraction voltages, and thruster command transients. Most notably, we experimentally observed skewed cone-jet emission during steady-state electrospray thruster operation, which leads to the definition of an additional grid impingement mechanism that we termed “tilted emission”. Long distance microscopy was used in conjunction with high speed videography to observe the emission site of an electrospray thruster operating with an ionic liquid propellant (EMI-Im). During steady-state thruster operation, no unsteady electrohydrodynamic emission modes were observed, though the conical meniscus exhibited steady off-axis tilt of up to 15°. Cone tilt angle was independent over a wide range of flow rates but proved strongly dependent on extraction voltage. For the geometry and propellant used, the optimal extraction voltage was near 1.6 kV. A second experiment characterized transient emission behavior by observing startup and shutdown of the thruster via flow or voltage. Three of the four possible startup and shutdown procedures transition to quiescence within ∼475 μs, with no observed unsteady modes. However, during voltage-induced thruster startup, unsteady electrohydrodynamic modes were observed.

scholarly journals A Microfabricated Planar Electrospray Array Ionic Liquid Ion Source With Integrated Extractor

2009 ◽  
Vol 18 (3) ◽  
pp. 679-694 ◽  
Author(s):  
B. Gassend ◽  
L.F. Velasquez-Garcia ◽  
A.I. Akinwande ◽  
M. Martinez-Sanchez
Keyword(s):  
Ionic Liquid ◽  
Ion Source

SOME EXACT SOLUTIONS OF THE LORENTZ INVARIANT PROBLEM OF THE MOTION OF TWO ELECTRIC FLUIDS

1955 ◽  
Vol 33 (12) ◽  
pp. 819-823 ◽  
Author(s):  
J. J. Gibbons
Keyword(s):  
Steady State ◽  
Exact Solutions ◽  
Cylindrical Symmetry ◽  
Axially Symmetric ◽  
Two Fluids ◽  
Body Forces ◽  
Steady State Solutions

Methods of generating exact steady-state solutions for the flow of superimposed positive and negative fluids are developed for the cases of linear and cylindrical motion. The two fluids are assumed to be subject only to body forces arising from the total E and B fields. It is shown that the only axially symmetric solutions are of cylindrical symmetry, i.e. rotating spheres or rings of charge cannot satisfy the equations where the two fluids overlap.

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