Magnetic and electric field waves in slow shocks of the distant geomagnetic tail: ISEE 3 observations

1994 ◽  
Vol 99 (A6) ◽  
pp. 11251 ◽  
Author(s):  
F. V. Coroniti ◽  
S. L. Moses ◽  
E. W. Greenstadt ◽  
B. T. Tsurutani ◽  
E. J. Smith
Keyword(s):  
Electric Field ◽  
Geomagnetic Tail

scholarly journals The Acceleration of Outer-Belt Electrons by Localized Electric Fields

2021 ◽  
Vol 61 (4) ◽  
pp. 477-482
Author(s):  
A. P. Kropotkin
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Relativistic Electrons ◽  
Strong Component ◽  
Short Term ◽  
Energetic Electrons ◽  
Geomagnetic Tail ◽  
Night Side ◽  
Bursty Bulk Flows

Abstract To explain the populations of the outer-belt energetic electrons, including relativistic electrons, that sporadically appear in the magnetosphere, a mechanism was proposed long ago for the acceleration of those electrons by short-term bursts of the electric field, which appear on the night side during substorm disturbances (Kropotkin, 1996). This mechanism can be substantially specified if the modern concepts of bursty bulk flows in the geomagnetic tail, the occurrence of dipolarization fronts, and the excitation of localized field-aligned-resonant poloidal Alfvén oscillations involving a strong component of the electric field in the dawn-dusk direction are taken into account.

scholarly journals Resistive MHD reconstruction of two-dimensional coherent structures in space

2010 ◽  
Vol 28 (11) ◽  
pp. 2113-2125 ◽  
Author(s):  
W.-L. Teh ◽  
B. U. Ö. Sonnerup ◽  
J. Birn ◽  
R. E. Denton
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Synthetic Data ◽  
Two Dimensions ◽  
Mhd Equations ◽  
Numerical Code ◽  
Reconstruction Technique ◽  
Two Dimensional ◽  
Geomagnetic Tail ◽  
Spacecraft Spin

Abstract. We present a reconstruction technique to solve the steady resistive MHD equations in two dimensions with initial inputs of field and plasma data from a single spacecraft as it passes through a coherent structure in space. At least two components of directly measured electric fields (the spacecraft spin-plane components) are required for the reconstruction, to produce two-dimensional (2-D) field and plasma maps of the cross section of the structure. For convenience, the resistivity tensor η is assumed diagonal in the reconstruction coordinates, which allows its values to be estimated from Ohm's law, E+v×B=η·j. In the present paper, all three components of the electric field are used. We benchmark our numerical code by use of an exact, axi-symmetric solution of the resistive MHD equations and then apply it to synthetic data from a 3-D, resistive, MHD numerical simulation of reconnection in the geomagnetic tail, in a phase of the event where time dependence and deviations from 2-D are both weak. The resistivity used in the simulation is time-independent and localized around the reconnection site in an ellipsoidal region. For the magnetic field, plasma density, and pressure, we find very good agreement between the reconstruction results and the simulation, but the electric field and plasma velocity are not predicted with the same high accuracy.

Pioneer 8 electric field measurements in the distant geomagnetic tail

1970 ◽  
Vol 75 (16) ◽  
pp. 3167-3179 ◽  
Author(s):  
F. L. Scarf ◽  
I. M. Green ◽  
G. L. Siscoe ◽  
D. S. Intriligator ◽  
D. D. McKibbin ◽  
...  
Keyword(s):  
Electric Field ◽  
Field Measurements ◽  
Geomagnetic Tail ◽  
Electric Field Measurements

Resolution in photoelectron microscopy

1991 ◽  
Vol 49 ◽  
pp. 458-459
Author(s):  
G. F. Rempfer
Keyword(s):  
Electron Microscopy ◽  
Electric Field ◽  
Ultraviolet Light ◽  
Uniform Field ◽  
Virtual Image ◽  
Lens System ◽  
Photoemission Electron Microscopy ◽  
Planar Electrode ◽  
Electron Lens ◽  
Photoemission Electron

In photoelectron microscopy (PEM), also called photoemission electron microscopy (PEEM), the image is formed by electrons which have been liberated from the specimen by ultraviolet light. The electrons are accelerated by an electric field before being imaged by an electron lens system. The specimen is supported on a planar electrode (or the electrode itself may be the specimen), and the accelerating field is applied between the specimen, which serves as the cathode, and an anode. The accelerating field is essentially uniform except for microfields near the surface of the specimen and a diverging field near the anode aperture. The uniform field forms a virtual image of the specimen (virtual specimen) at unit lateral magnification, approximately twice as far from the anode as is the specimen. The diverging field at the anode aperture in turn forms a virtual image of the virtual specimen at magnification 2/3, at a distance from the anode of 4/3 the specimen distance. This demagnified virtual image is the object for the objective stage of the lens system.

Field-assisted ionization theory for microscopists

1994 ◽  
Vol 52 ◽  
pp. 820-821
Author(s):  
Patrick P. Camus
Keyword(s):  
Electric Field ◽  
Electron Tunneling ◽  
Ionization Probability ◽  
Critical Distance ◽  
Tunneling Probability ◽  
Field Ionization ◽  
Radius Of Curvature ◽  
Field Evaporation ◽  
A Value ◽  
Ion Emission

The theory of field ion emission is the study of electron tunneling probability enhanced by the application of a high electric field. At subnanometer distances and kilovolt potentials, the probability of tunneling of electrons increases markedly. Field ionization of gas atoms produce atomic resolution images of the surface of the specimen, while field evaporation of surface atoms sections the specimen. Details of emission theory may be found in monographs.Field ionization (FI) is the phenomena whereby an electric field assists in the ionization of gas atoms via tunneling. The tunneling probability is a maximum at a critical distance above the surface,xc, Fig. 1. Energy is required to ionize the gas atom at xc, I, but at a value reduced by the appliedelectric field, xcFe, while energy is recovered by placing the electron in the specimen, φ. The highest ionization probability occurs for those regions on the specimen that have the highest local electric field. Those atoms which protrude from the average surfacehave the smallest radius of curvature, the highest field and therefore produce the highest ionizationprobability and brightest spots on the imaging screen, Fig. 2. This technique is called field ion microscopy (FIM).

Linear growth of instabilities on a liquid metal under normal electric field

1993 ◽  
Vol 3 (8) ◽  
pp. 1201-1225 ◽  
Author(s):  
G. N�ron de Surgy ◽  
J.-P. Chabrerie ◽  
O. Denoux ◽  
J.-E. Wesfreid
Keyword(s):  
Liquid Metal ◽  
Electric Field ◽  
Linear Growth ◽  
Normal Electric Field
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