Ionospheric electron heating by structured electric fields: Theory and experiment

1996 ◽  
Vol 101 (A5) ◽  
pp. 10893-10907 ◽  
Author(s):  
Ludmila M. Kagan ◽  
Michael C. Kelley ◽  
Richard A. Doe
Keyword(s):  
Electric Fields ◽  
Electron Heating ◽  
Theory And Experiment

Electrohydrodynamic stability: Taylor–Melcher theory for a liquid bridge suspended in a dielectric gas

2002 ◽  
Vol 452 ◽  
pp. 163-187 ◽  
Author(s):  
C. L. BURCHAM ◽  
D. A. SAVILLE
Keyword(s):  
Surface Tension ◽  
Dielectric Constant ◽  
Electric Fields ◽  
Liquid Bridge ◽  
Numerical Solutions ◽  
Specific Conductivity ◽  
Axisymmetric Deformation ◽  
Aspect Ratios ◽  
The Stability ◽  
Theory And Experiment

A liquid bridge is a column of liquid, pinned at each end. Here we analyse the stability of a bridge pinned between planar electrodes held at different potentials and surrounded by a non-conducting, dielectric gas. In the absence of electric fields, surface tension destabilizes bridges with aspect ratios (length/diameter) greater than π. Here we describe how electrical forces counteract surface tension, using a linearized model. When the liquid is treated as an Ohmic conductor, the specific conductivity level is irrelevant and only the dielectric properties of the bridge and the surrounding gas are involved. Fourier series and a biharmonic, biorthogonal set of Papkovich–Fadle functions are used to formulate an eigenvalue problem. Numerical solutions disclose that the most unstable axisymmetric deformation is antisymmetric with respect to the bridge’s midplane. It is shown that whilst a bridge whose length exceeds its circumference may be unstable, a sufficiently strong axial field provides stability if the dielectric constant of the bridge exceeds that of the surrounding fluid. Conversely, a field destabilizes a bridge whose dielectric constant is lower than that of its surroundings, even when its aspect ratio is less than π. Bridge behaviour is sensitive to the presence of conduction along the surface and much higher fields are required for stability when surface transport is present. The theoretical results are compared with experimental work (Burcham & Saville 2000) that demonstrated how a field stabilizes an otherwise unstable configuration. According to the experiments, the bridge undergoes two asymmetric transitions (cylinder-to-amphora and pinch-off) as the field is reduced. Agreement between theory and experiment for the field strength at the pinch-off transition is excellent, but less so for the change from cylinder to amphora. Using surface conductivity as an adjustable parameter brings theory and experiment into agreement.

Mode conversion electron heating in Alcator C-Mod: Theory and experiment

2000 ◽  
Vol 7 (5) ◽  
pp. 1886-1893 ◽  
Author(s):  
P. T. Bonoli ◽  
M. Brambilla ◽  
E. Nelson-Melby ◽  
C. K. Phillips ◽  
M. Porkolab ◽  
...  
Keyword(s):  
Conversion Electron ◽  
Mode Conversion ◽  
Electron Heating ◽  
Theory And Experiment

Shift of the Critical Mixing Temperature in Strong Electric Fields. Theory and Experiment

2014 ◽  
Vol 118 (25) ◽  
pp. 7187-7194 ◽  
Author(s):  
Kazimierz Orzechowski ◽  
Mariusz Adamczyk ◽  
Alicja Wolny ◽  
Yoav Tsori
Keyword(s):  
Electric Fields ◽  
Strong Electric Fields ◽  
Critical Mixing ◽  
Theory And Experiment

scholarly journals Poker Flat Incoherent Scatter Radar observations of anomalous electron heating in the E region

2013 ◽  
Vol 31 (7) ◽  
pp. 1163-1176 ◽  
Author(s):  
R. A. Makarevich ◽  
A. V. Koustov ◽  
M. J. Nicolls
Keyword(s):  
Electric Field ◽  
Electron Temperature ◽  
Electric Fields ◽  
Linear Trend ◽  
Incoherent Scatter Radar ◽  
Electron Heating ◽  
Incoherent Scatter ◽  
Convection Electric Field ◽  
Scatter Radar ◽  
E Region

Abstract. A comprehensive 2-year dataset collected with the Poker Flat Incoherent Scatter Radar (PFISR) located near Fairbanks, Alaska (MLAT = 65.4° N) is employed to identify and analyse 22 events of anomalous electron heating (AEH) in the auroral E region. The overall AEH occurrence probability is conservatively estimated to be 0.3% from nearly-continuous observations of the E region by PFISR, although it increases to 0.7–0.9% in the dawn and dusk sectors where all AEH events were observed. The AEH occurrence variation with MLT is broadly consistent with those of events with high convection velocity (>1000 m s−1) or electron temperature (> 800 K), except for much smaller AEH probability and absence of AEH events near magnetic midnight. This suggests that high convection electric field by itself is necessary but not sufficient for measurable electron heating by two-stream plasma waves. The multi-point observations are utilised to investigate the fundamental dependence of the electron temperature on the convection electric field, focusing on the previously-proposed saturation effects at extreme electric fields. The AEH dataset was found to exhibit considerable scatter and, on average, similar rate of the electron temperature increase with the electric field up to 100 mV m−1 as compared with previous studies. At higher (highest) electric fields, the electron temperatures are below the linear trend on average (within uncertainty). By employing a simple fluid model of AEH, it is demonstrated that some of this deviation from the linear trend may be due to a stronger vibrational cooling at very large temperatures and electric fields.

Beam deviation of large polar molecules in static electric fields: theory and experiment

2001 ◽  
Vol 336 (5-6) ◽  
pp. 511-517 ◽  
Author(s):  
Philippe Dugourd ◽  
Isabelle Compagnon ◽  
Franck Lepine ◽  
Rodolphe Antoine ◽  
Driss Rayane ◽  
...  
Keyword(s):  
Electric Fields ◽  
Polar Molecules ◽  
Static Electric Fields ◽  
Theory And Experiment

Effect of electron heating by surface electric fields on oscillating photoresponse spectra of gallium arsenide-metal structures

1981 ◽  
Vol 65 (1) ◽  
pp. 259-263 ◽  
Author(s):  
V. L. Alperovich ◽  
A. F. Kravchenko ◽  
N. A. Pakhanov ◽  
A. S. Terekhov
Keyword(s):  
Gallium Arsenide ◽  
Electric Fields ◽  
Electron Heating ◽  
Metal Structures

ELECTRON HEATING IN QUANTUM-DOT STRUCTURES WITH COLLECTIVE POTENTIAL BARRIERS

2011 ◽  
Vol 20 (01) ◽  
pp. 143-152 ◽  
Author(s):  
L.H. CHIEN ◽  
A. SERGEEV ◽  
N. VAGIDOV ◽  
V. MITIN ◽  
S. BIRNER
Keyword(s):  
Quantum Dots ◽  
Monte Carlo ◽  
Quantum Dot ◽  
Electric Field ◽  
Monte Carlo Simulations ◽  
Electric Fields ◽  
Geometrical Parameters ◽  
Electron Heating ◽  
Potential Barriers ◽  
Strong Electric Fields

Here we report our research on quantum-dot structures with collective barriers surrounding groups of quantum dots (planes, clusters etc) and preventing photoelectron capture. Employing Monte-Carlo simulations, we investigate photoelectron kinetics and calculate the photoelectron lifetime as a function of geometrical parameters of the structures, dot occupation, and electric field. Results of our simulations demonstrate that the capture processes are substantially suppressed by the potential barriers and enhanced in strong electric fields. Detailed analysis shows that the effects of the electric field can be explained by electron heating, i.e. field effects become significant, when the shift of the electron temperature due to electron heating reaches the barrier height. Optimized photoelectron kinetics in quantum-dot structures with collective barriers allows for significant improvements in the photoconductive gain, detectivity, and responsivity of photodetectors based on these structures.

scholarly journals The effect of ambipolar electric fields on the electron heating in capacitive RF plasmas

2014 ◽  
Vol 24 (1) ◽  
pp. 015019 ◽  
Author(s):  
J Schulze ◽  
Z Donkó ◽  
A Derzsi ◽  
I Korolov ◽  
E Schuengel
Keyword(s):  
Electric Fields ◽  
Electron Heating ◽  
Rf Plasmas
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