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 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

Effect of ion temperature on ion-acoustic solitary waves: a pseudopotential approach

1987 ◽  
Vol 65 (7) ◽  
pp. 699-702 ◽  
Author(s):  
R. K. Roychoudhury ◽  
Sikha Bhattacharyya
Keyword(s):  
Mach Number ◽  
Solitary Waves ◽  
Soliton Solution ◽  
Ion Temperature ◽  
Collisionless Plasmas ◽  
Ion Acoustic Solitary Waves ◽  
Ion Acoustic ◽  
Cold Ions ◽  
Pseudopotential Approach ◽  
Published Result

Using the pseudopotential approach of Sagdeev, we have found analytically exact conditions for the existence of solitary waves for a system of collisionless plasmas with a mixture of warm ion-fluid and hot isothermal electrons. The analytical soliton solution for small amplitudes has also been obtained and has been compared with the published result. It is found that the finite ion temperature considerably modifies the restriction on the Mach number obtained for cold ions.

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>

scholarly journals Structural Characteristics of Ion Holes in Plasma

Plasma ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 435-449
Author(s):  
Harikrishnan Aravindakshan ◽  
Amar Kakad ◽  
Bharati Kakad ◽  
Peter H. Yoon
Keyword(s):  
Structural Characteristics ◽  
Space Structures ◽  
Ion Temperature ◽  
Temperature Ratio ◽  
Ion Density ◽  
Trapped Ion ◽  
Multiple Parameters ◽  
Collisionless Plasmas ◽  
Plasma Distribution

Ion holes refer to the phase-space structures where the trapped ion density is lower at the center than at the rim. These structures are commonly observed in collisionless plasmas, such as the Earth’s magnetosphere. This paper investigates the role of multiple parameters in the generation and structure of ion holes. We find that the ion-to-electron temperature ratio and the background plasma distribution function of the species play a pivotal role in determining the physical plausibility of ion holes. It is found that the range of width and amplitude that defines the existence of ion holes splits into two separate domains as the ion temperature exceeds that of the electrons. Additionally, the present study reveals that the ion holes formed in a plasma with ion temperature higher than that of the electrons have a hump at its center.

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.

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