scholarly journals Electrostatic potentials in the downward auroral current region

2005 ◽  
Vol 110 (A8) ◽  
Author(s):  
Jörgen Vedin ◽  
Kjell Rönnmark
Keyword(s):  
Electrostatic Potentials ◽  
Current Region ◽  
Auroral Current

scholarly journals Downward auroral currents from the reconnection Hall-region

2011 ◽  
Vol 29 (4) ◽  
pp. 679-685
Author(s):  
R. A. Treumann ◽  
R. Nakamura ◽  
W. Baumjohann
Keyword(s):  
Electromotive Force ◽  
Electron Flow ◽  
Electrons And Ions ◽  
Low Latitudes ◽  
Outflow Region ◽  
Current Region ◽  
Collisionless Reconnection ◽  
Downward Currents ◽  
Auroral Current ◽  
Fast Reconnection

Abstract. We present a simple (stationary) mechanism capable of generating the auroral downward field-aligned electric field that is needed for accelerating the ionospheric electron component up into the magnetosphere and confining the ionospheric ions at low latitudes (as is required by observation of an ionospheric cavity in the downward auroral current region). The lifted ionospheric electrons carry the downward auroral current. Our model is based on the assumption of collisionless reconnection in the tail current sheet. It makes use of the dynamical difference between electrons and ions in the ion inertial region surrounding the reconnection X-line which causes Hall currents to flow. We show that the spatial confinement of the Hall magnetic field and flux to the ion inertial region centred on the X-point generates a spatially variable electromotive force which is positive near the outer inflow boundaries of the ion inertial region and negative in the central inflow region. Looked at from the ionosphere it functions like a localised meso-scale electric potential. The positive electromotive force gives rise to upward electron flow from the ionosphere during substorms (causing "black aurorae"). A similar positive potential is identified on the earthward side of the fast reconnection outflow region which has the same effect, explaining the observation that auroral upward currents are flanked from both sides by narrow downward currents.

FAST observations in the downward auroral current region: Energetic upgoing electron beams, parallel potential drops, and ion heating

1998 ◽  
Vol 25 (12) ◽  
pp. 2017-2020 ◽  
Author(s):  
C. W. Carlson ◽  
J. P. McFadden ◽  
R. E. Ergun ◽  
M. Temerin ◽  
W. Peria ◽  
...  
Keyword(s):  
Electron Beams ◽  
Ion Heating ◽  
Current Region ◽  
Auroral Current

Interactive multiobjective DEA target setting using lexicographic DDF

2020 ◽  
Vol 54 (6) ◽  
pp. 1703-1722 ◽  
Author(s):  
Narges Soltani ◽  
Sebastián Lozano
Keyword(s):  
Efficient Frontier ◽  
Directional Distance Function ◽  
Fixed Number ◽  
Optimization Approach ◽  
Target Setting ◽  
Interactive Process ◽  
Decision Making Unit ◽  
Setting Approach ◽  
Promising Area ◽  
Current Region

In this paper, a new interactive multiobjective target setting approach based on lexicographic directional distance function (DDF) method is proposed. Lexicographic DDF computes efficient targets along a specified directional vector. The interactive multiobjective optimization approach consists in several iteration cycles in each of which the Decision Making Unit (DMU) is presented a fixed number of efficient targets computed corresponding to different directional vectors. If the DMU finds one of them promising, the directional vectors tried in the next iteration are generated close to the promising one, thus focusing the exploration of the efficient frontier on the promising area. In any iteration the DMU may choose to finish the exploration of the current region and restart the process to probe a new region. The interactive process ends when the DMU finds its most preferred solution (MPS).

A Graphical Method to Study Electrostatic Potentials of 25 nm Channel Length DG SOI MOSFETs

2018 ◽  
Vol 10 (4) ◽  
pp. 04027-1-04027-4
Author(s):  
M. Djerioui ◽  
◽  
M. Hebali ◽  
D. Chalabi ◽  
A. Saidane ◽  
...  
Keyword(s):  
Graphical Method ◽  
Channel Length ◽  
Electrostatic Potentials

Some Approximate Atomic and Molecular Energy Formulas

2003 ◽  
Vol 68 (1) ◽  
pp. 61-74 ◽  
Author(s):  
Peter Politzer ◽  
Abraham F. Jalbout ◽  
Ping Jin
Keyword(s):  
Density Functional ◽  
Electrostatic Potentials ◽  
Hartree Fock ◽  
Chemical Potentials ◽  
Approximate Formulas

We have tested several approximate formulas that relate atomic and molecular energies to the electrostatic potentials at the nuclei, V0 and V0,A, respectively. They are based upon the assumption that the chemical potentials can be neglected relative to V0 and V0,A. Exact, Hartree-Fock and density-functional values were used for the latter. The results are overall encouraging; the errors in the energies generally decrease markedly as the nuclear charges Z increase and the assumptions become more valid. Improvement is needed, however, in fitting the V0 and V0,A to Z.

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