Slow electron holes in multicomponent plasmas

2015 ◽  
Vol 42 (18) ◽  
pp. 7264-7272 ◽  
Author(s):  
C. Norgren ◽  
M. André ◽  
D. B. Graham ◽  
Yu. V. Khotyaintsev ◽  
A. Vaivads
Keyword(s):  
Slow Electron ◽  
Electron Holes

scholarly journals Ultra slow electron holes in collisionless plasmas: Stability at high ion temperature

2020 ◽  
Vol 27 (2) ◽  
pp. 022102
Author(s):  
Debraj Mandal ◽  
Devendra Sharma ◽  
Hans Schamel
Keyword(s):  
Slow Electron ◽  
Ion Temperature ◽  
Collisionless Plasmas ◽  
Electron Holes

Electron holes in the Earth's magnetotail current sheet: role of magnetic field gradients and electron anisotropy

2020 ◽  
Author(s):  
Pavel Shustov ◽  
Ilya Kuzichev ◽  
Ivan Vasko ◽  
Anton Artemyev ◽  
Anatoliy Petrukovich
Keyword(s):  
Magnetic Field ◽  
Current Sheet ◽  
Magnetic Field Gradient ◽  
Electron Distribution Function ◽  
Inhomogeneous Magnetic Field ◽  
Field Configuration ◽  
Slow Electron ◽  
Electron Hole ◽  
Field Lines ◽  
Electron Holes

<p>Electron holes are nonlinear electrostatic structures that are often observed in the vicinity of the magnetotail energy release regions, e.g. magnetic reconnection. In this work we develop 1.5D Vlasov code simulations of the electron hole dynamics in the magnetic field configuration typical of the current sheet of the Earth's magnetotail. We consider the propagation of electron holes along magnetic field lines in the inhomogeneous magnetic field of the current sheet with realistically anisotropic electron distribution function. We demonstrate that electron holes generated near the equatorial plane of the current sheet brake as they propagate toward the boundaries of the current sheets. This effect is stronger for higher magnetic field gradient and larger electron field-aligned anisotropy. These simulations demonstrate that slow electron holes observed in the plasma sheet boundary layer may appear due to that effect of electron hole braking.</p>

Slow electrostatic solitary waves in the Earth's magnetosphere

2021 ◽  
Author(s):  
Sergey Kamaletdinov ◽  
Ivan Vasko ◽  
Egor Yushkov ◽  
Anton Artemyev ◽  
Rachel Wang
Keyword(s):  
Solitary Waves ◽  
Rest Frame ◽  
Spatial Scales ◽  
Plasma Heating ◽  
Theoretical Models ◽  
Slow Electron ◽  
Local Electron ◽  
Russian Scientific ◽  
The Earth ◽  
Electron Holes

<p>Slow electron holes, that are electrostatic solitary waves propagating with velocities comparable to the ion thermal velocity, can contribute to plasma heating and provide an anomalous resistivity in various space plasma systems. In addition, the analysis of electron holes allows revealing instabilities operating on time scales not resolved by plasma instruments. We present experimental analysis of more than 100 slow electron holes in the Earth’s bow shock and more than 1000 slow electron holes in the Earth’s nightside magnetosphere. We show that in both regions, the electron holes have similar parameters. The spatial scales are in the range from 1 to 10 Debye lengths, amplitudes of the electrostatic potential are typically below 0.1 of local electron temperature, velocities in the plasma rest frame are of the order of local ion-acoustic velocity. We show that in both regions the electron holes are most likely produced by Buneman-type instabilities. We develop theoretical models of the electron holes and compare them to MMS observations. The lifetime and the transverse instability of the electron holes are discussed.</p><p>This work was supported by the Russian Scientific Foundation, Project No. 19–<span>12-00313</span></p>

Observations of Slow Electron Holes at a Magnetic Reconnection Site

2010 ◽  
Vol 105 (16) ◽  
Author(s):  
Yu. V. Khotyaintsev ◽  
A. Vaivads ◽  
M. André ◽  
M. Fujimoto ◽  
A. Retinò ◽  
...  
Keyword(s):  
Magnetic Reconnection ◽  
Slow Electron ◽  
Reconnection Site ◽  
Electron Holes

Direct imaging of charge transfer

1996 ◽  
Vol 54 ◽  
pp. 680-681
Author(s):  
Yimei Zhu ◽  
J. Tafto
Keyword(s):  
Charge Transfer ◽  
Electron Diffraction ◽  
Scattering Amplitude ◽  
High Temperature Superconductors ◽  
Charge Carriers ◽  
Image Charge ◽  
Net Charge ◽  
Long Time ◽  
Electron Holes ◽  
First Time

The electron holes confined to the CuO2-plane are the charge carriers in high-temperature superconductors, and thus, the distribution of charge plays a key role in determining their superconducting properties. While it has been known for a long time that in principle, electron diffraction at low angles is very sensitive to charge transfer, we, for the first time, show that under a proper TEM imaging condition, it is possible to directly image charge in crystals with a large unit cell. We apply this new way of studying charge distribution to the technologically important Bi2Sr2Ca1Cu2O8+δ superconductors.Charged particles interact with the electrostatic potential, and thus, for small scattering angles, the incident particle sees a nuclei that is screened by the electron cloud. Hence, the scattering amplitude mainly is determined by the net charge of the ion. Comparing with the high Z neutral Bi atom, we note that the scattering amplitude of the hole or an electron is larger at small scattering angles. This is in stark contrast to the displacements which contribute negligibly to the electron diffraction pattern at small angles because of the short g-vectors.

Electrochemical behaviour and ESR spectra of nitro substituted mono- and dibenzoylmethylenebenzthiazolines and selenazolines

1979 ◽  
Vol 44 (5) ◽  
pp. 1540-1551 ◽  
Author(s):  
Jaro Komenda ◽  
Jiří Huzlík
Keyword(s):  
Electron Transfer ◽  
Esr Spectroscopy ◽  
Electrochemical Behaviour ◽  
Spectroscopic Studies ◽  
Esr Spectra ◽  
Slow Electron

Compounds of the type of 2-(4'-nitrobenzoyl)methylene-3-ethylbenzothiazoline (I) and 2-bis-(p-nitrobenzoyl)methylene-3-ethylbenzothiazoline (II) were studied polarographically and by ESR spectroscopy to obtain informations about their electrochemical and follow-up reactions and their conformation. Whereas with compounds of the type I the conjugation in their molecules is preserved, with type II the coplanarity of the molecules is disturbed, which is manifested in the values of the splitting constants of the ESR spectra and a slow electron transfer between both nitrophenyl substituents. These conclusions are supported by NMR spectroscopic studies.

Doping Effect in Nickel Oxide

2009 ◽  
Vol 289-292 ◽  
pp. 775-782 ◽  
Author(s):  
Zbigniew Jurasz ◽  
Krzysztof Adamaszek ◽  
Romuald Janik ◽  
Zbigniew Grzesik ◽  
Stanisław Mrowec
Keyword(s):  
Activation Energy ◽  
Nickel Oxide ◽  
High Temperatures ◽  
Oxygen Pressure ◽  
Pressure Dependence ◽  
Oxidation Rate ◽  
Doping Effect ◽  
Self Diffusion ◽  
Electron Holes ◽  
Influence Of Impurities

Detailed investigations of nonstoichiometry as well as chemical and self-diffusion in nickel oxide have shown that doubly ionised cation vacancies and electron holes are the predominant defects in this material. The present work is an attempt to demonstrate that aliovalent impurities (Cr, Al, Na and Li) may considerably influence the concentration of these defects and, consequently, the oxidation rate of nickel at high temperatures. It has been shown that small amounts of tri-valent impurities (Cr, Al) bring about an increase of the oxidation rate, while mono-valent ones (Li, Na) decrease the rate of oxidation. These phenomena may satisfactorily be explained in terms of a doping effect. All experiments have been carried out as a function of temperature (1373-1673 K) and oxygen pressure (1-105 Pa) and consequently, it was possible to determine the influence of impurities not only on the oxidation rate but also on the activation energy of reaction and its pressure dependence. The results of these investigations could again be elucidated in terms of doping effect.

scholarly journals Application of BiOX Photocatalysts in Remediation of Persistent Organic Pollutants

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 604 ◽  
Author(s):  
Robert Arthur ◽  
John Ahern ◽  
Howard Patterson
Keyword(s):  
Photocatalytic Degradation ◽  
Organic Pollutants ◽  
Persistent Organic Pollutants ◽  
Radical Scavenging ◽  
Flow Chemistry ◽  
Active Species ◽  
Effective Strategies ◽  
Degradation Of Dyes ◽  
Bismuth Oxyhalides ◽  
Electron Holes

Bismuth oxyhalides have recently gained attention for their promise as photocatalysts. Due to their layered structure, these materials present fascinating and highly desirable physicochemical properties including visible light photocatalytic capability and improved charge separation. While bismuth oxyhalides have been rigorously evaluated for the photocatalytic degradation of dyes and many synthesis strategies have been employed to enhance this property, relatively little work has been done to test them against pharmaceuticals and pesticides. These persistent organic pollutants are identified as emerging concerns by the EPA and effective strategies must be developed to combat them. Here, we review recent work directed at characterizing the nature of the interactions between bismuth oxyhalides and persistent organic pollutants using techniques including LC-MS/MS for the determination of photocatalytic degradation intermediates and radical scavenging to determine active species during photocatalytic degradation. The reported investigations indicate that the high activity of bismuth oxyhalides for the breakdown of persistent organic pollutants from water can be largely attributed to the strong oxidizing power of electron holes in the valence band. Unlike conventional catalysts like TiO2, these catalysts can also function in ambient solar conditions. This suggests a much wider potential use for these materials as green catalysts for industrial photocatalytic transformation, particularly in flow chemistry applications.

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