Current sheets with inhomogeneous plasma temperature: Effects of polarization electric field and 2D solutions

2015 ◽  
Vol 22 (9) ◽  
pp. 092905 ◽  
Author(s):  
F. Catapano ◽  
A. V. Artemyev ◽  
G. Zimbardo ◽  
I. Y. Vasko
Keyword(s):  
Electric Field ◽  
Temperature Effects ◽  
Inhomogeneous Plasma ◽  
Plasma Temperature ◽  
Current Sheets ◽  
Polarization Electric Field

Triggering photocatalytic activity of carbon dot-based nanocomposites by self-supplying peroxide

2021 ◽  
Author(s):  
Tingting Cai ◽  
Qing Chang ◽  
Bin Liu ◽  
Caihong Hao ◽  
Jinlong Yang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Electric Field ◽  
Catalytic Process ◽  
Charge Accumulation ◽  
Carbon Dot ◽  
Carrier Transfer ◽  
Polarization Electric Field

The photocatalyst performance highly relies on the quantity of carrier transfer from the bulk to surface during the catalytic process. However, the polarization electric field induced by charge accumulation at...

scholarly journals A thermodynamic approach to rate-type models in deformable ferroelectrics

2020 ◽  
Author(s):  
Claudio Giorgi ◽  
Angelo Morro
Keyword(s):  
Free Energy ◽  
Electric Field ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Energy Models ◽  
Polarization Electric Field ◽  
Field Plane ◽  
Vector Valued ◽  
Rate Type ◽  
Hysteretic Properties

AbstractThe purpose of the paper is to establish vector-valued rate-type models for the hysteretic properties in deformable ferroelectrics within the framework of continuum thermodynamics. Unlike electroelasticity and piezoelectricity, in ferroelectricity both the polarization and the electric field are simultaneously independent variables so that the constitutive functions depend on both. This viewpoint is naturally related to the fact that an hysteresis loop is a closed curve in the polarization–electric field plane. For the sake of generality, the deformation of the material and the dependence on the temperature are allowed to occur. The constitutive functions are required to be consistent with the principle of objectivity and the second law of thermodynamics. Objectivity implies that the constitutive equations are form invariant within the set of Euclidean frames. Among other results, the second law requires a general property on the relation between the polarization and the electric field via a differential equation. This equation shows a dependence fully characterized by two quantities: the free energy and a function which is related to the dissipative character of the hysteresis. As a consequence, different hysteresis models may have the same free energy. Models compatible with thermodynamics are then determined by appropriate selections of the free energy and of the dissipative part. Correspondingly, major and minor hysteretic loops are plotted.

scholarly journals Motion of Flare Footpoint Emission and Inferred Electric Field in Reconnecting Current Sheets

2002 ◽  
Vol 565 (2) ◽  
pp. 1335-1347 ◽  
Author(s):  
Jiong Qiu ◽  
Jeongwoo Lee ◽  
Dale E. Gary ◽  
Haimin Wang
Keyword(s):  
Electric Field ◽  
Current Sheets

Parametric excitation in an inhomogeneous plasma

1971 ◽  
Vol 5 (1) ◽  
pp. 107-113 ◽  
Author(s):  
C. S. Chen
Keyword(s):  
Electric Field ◽  
Parametric Excitation ◽  
Growth Rates ◽  
Inhomogeneous Plasma ◽  
Electron Plasma ◽  
Transverse Waves ◽  
Circularly Polarized ◽  
Polarized Waves ◽  
Oscillating Electric Field ◽  
Unmagnetized Plasma

An infinite, inhomogeneous electron plasma driven by a spatially uniform oscillating electric field is investigated. The multi-time perturbation method is used to analyze possible parametric excitations of transverse waves and to evaluate their growth rates. It is shown that there exist subharmonic excitations of: (1) a pair of transverse waves in an unmagnetized plasma and (2) a pair of one right and one left circularly polarized wave in a magnetoplasma. Additionally, parametric excitation of two right or two left circularly polarized waves with different frequencies can exist in a magnetoplasma. The subharmonic excitations are impossible whenever the density gradient and the applied electric field are perpendicular. However, parametric excitation is possible with all configurations.

scholarly journals Effect of interchange instability on magnetic reconnection

2013 ◽  
Vol 20 (3) ◽  
pp. 365-377 ◽  
Author(s):  
W. Lyatsky ◽  
M. L. Goldstein
Keyword(s):  
Magnetic Fields ◽  
Electric Field ◽  
Magnetic Reconnection ◽  
Plasma Flow ◽  
Buoyancy Force ◽  
Strong Turbulence ◽  
Polarization Electric Field ◽  
Interchange Instability ◽  
Reconnection Layer ◽  
Fast Reconnection

Abstract. We present here the results of a study of interacting magnetic fields that involves a force normal to the reconnection layer. In the presence of such force, the reconnection layer becomes unstable to interchange disturbances. The interchange instability results in formation of tongues of heated plasma that leaves the reconnection layer through its wide surface rather than through its narrow ends, as is the case in traditional magnetic reconnection models. This plasma flow out of the reconnection layer facilitates the removal of plasma from the layer and leads to fast reconnection. The proposed mechanism provides fast reconnection of interacting magnetic fields and does not depend on the thickness of the reconnection layer. This instability explains the strong turbulence and bidirectional streaming of plasma that is directed toward and away from the reconnection layer that is observed frequently above reconnection layers. The force normal to the reconnection layer also accelerates the removal of plasma islands appearing in the reconnection layer during turbulent reconnection. In the presence of this force normal to the reconnection layer, these islands are removed from the reconnection layer by the "buoyancy force", as happens in the case of interchange instability that arises due to the polarization electric field generated at the boundaries of the islands.

scholarly journals Моделирование плазмы короткодугового ксенонового разряда сверхвысокого давления

2019 ◽  
Vol 89 (10) ◽  
pp. 1556
Author(s):  
Н.А. Тимофеев ◽  
В.С. Сухомлинов ◽  
G. Zissis ◽  
И.Ю. Мухараева ◽  
Д.В. Михайлов ◽  
...  
Keyword(s):  
Experimental Data ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Arc Discharge ◽  
Plasma Temperature ◽  
Cathode Region ◽  
Ultrahigh Pressure ◽  
Thoriated Tungsten ◽  
Ionization Balance

AbstractWe have studied a high- (ultrahigh-) pressure short-arc discharge in xenon with thoriated tungsten cathodes. A system of equations formulated based on earlier experimental data indicating possible emission of cathode material (thorium) into the discharge gap has made it possible to determine the electric field strength, plasma temperature, and concentration of thorium atoms as well as thorium and xenon ions in the plasma. The problem has been solved for a model discharge between planar electrodes. The results indicate the key role of thorium atoms in the cathode region. Thorium atoms determine the ionization balance and other electrokinetic properties of plasma. Emission of thorium atoms reduces the plasma temperature at the cathode, which turns out to be noticeably lower than the plasma temperature near the anode; this is a new result that agrees with experimental data. Other electrokinetic characteristics of the plasma (in particular, charged particle concentration and electric field strength) are also in good agreement with the experiment.

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