scholarly journals Discharge processes, electric field, and electron energy in ISUAL-recorded gigantic jets

2009 ◽  
Vol 114 (A4) ◽  
pp. n/a-n/a ◽  
Author(s):  
Cheng-Ling Kuo ◽  
J. K. Chou ◽  
L. Y. Tsai ◽  
A. B. Chen ◽  
H. T. Su ◽  
...  
Keyword(s):  
Electric Field ◽  
Electron Energy ◽  
Gigantic Jets

scholarly journals Electron Mobility in Liquid Argon

1959 ◽  
Vol 12 (1) ◽  
pp. 105 ◽  
Author(s):  
FD Stacey
Keyword(s):  
Kinetic Theory ◽  
Electric Field ◽  
Electron Energy ◽  
Cross Section ◽  
Drift Velocity ◽  
Electron Mobility ◽  
Alternative Explanation ◽  
Liquid Argon ◽  
Scattering Cross Section ◽  
Scattering Cross

Experiments of Williams (1957) showed that the drift velocity of electrons in liquid argon to which an electric field F is applied is essentially independent of F. If the electrons remain free then their motion can be described by kinetic theory, from which it appears that electron mobility is proportional to F-I and drift velocity to Fli. This is the dependence reported by Malkin and Schultz (1951), but it is evident that the recent, more exhaustive work of Williams (1957) is correct on this point and therefore that kinetic theory is not applicable to the problem. This theory could in principle be extended to explain a fieldindependent velocity, by supposing a special dependence upon electron energy of the scattering cross section for the collision of electrons with argon atoms, but this is very artificial and unnecessary in view of the alternative explanation suggested here; in any case it leaves further serious objections, which will also be discussed briefly.

Effect of spin–orbit coupling on the hot-electron energy relaxation in nanowires

2020 ◽  
Vol 34 (32) ◽  
pp. 2050322
Author(s):  
A. L. Vartanian ◽  
A. L. Asatryan ◽  
A. G. Stepanyan ◽  
K. A. Vardanyan ◽  
A. A. Kirakosyan
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electron Temperature ◽  
Electron Energy ◽  
Power Loss ◽  
Continuum Theory ◽  
Energy Relaxation ◽  
Spin Orbit ◽  
Hot Electron ◽  
Electrical Field Strength

The energy relaxation of hot electrons is proposed based on the spin–orbit (SO) interaction of both Rashba and Dresselhaus types with the effect of hot phonons. A continuum theory of optical phonons in nanowires taking into account the influence of confinement is used to study the hot-electron energy relaxation. The energy relaxation due to both confined (CO) and interface (IO) optical phonon emission on nanowire radius, electrical field strength, parameters of SO couplings and electron temperature is calculated. For considered values of the nanowire radius as well as other system parameters, scattering by IO phonons prevails over scattering by CO phonons. The presence of an electric field leads to the decrease of power loss in transitions between states with the same spin quantum numbers. With the increase of the electric field strength, the influence of the Dresselhaus SO interaction on the energy relaxation rate decreases. The effect of SO interaction does not change the previously obtained increasing dependence of power loss on electron temperature. The sensitivity of energy relaxation to the electric field also through the Rashba parameter allows controlling the rate of energy by electric field.

Transient behavior of drift and ionization in atmospheric pressure nitrogen discharge

2021 ◽  
Author(s):  
S K Dhali
Keyword(s):  
Electric Field ◽  
Electron Energy ◽  
Fluid Model ◽  
High Energy ◽  
Second Order ◽  
Rate Coefficients ◽  
Transient Phase ◽  
Transport Parameters ◽  
Streamer Discharge ◽  
Local Mean

Abstract The fluid models are frequently used to describe a non-thermal plasma such as a streamer discharge. The required electron transport data and rate coefficients for the fluid model are parametrized using the local field approximation (LFA) in first order models and the local-mean-energy approximation (LMEA) in second order models. We performed Monte Carlo simulations in Nitrogen gas with step changes in the E/N (reduced electric field) to study the behavior of the transport properties in the transient phase. During the transient phase of the simulation, we extract the instantaneous electron mean energy, which is different from the steady state mean electron energy, and the corresponding transport parameters and rate coefficients. Our results indicate that the mean electron energy is not a suitable parameter for mobility/drift of electrons due to big difference in momentum relaxation and energy relaxation. However, the high energy threshold rates such as ionization show a strong correlation to mean electron energy. In second order models where the energy-balance equation is solved, we suggest that it would rather be appropriate to use the local electric field to find electron drift velocity in gases such as Nitrogen and the local mean electron energy to determine the ionization and excitation rates.

A measurement of the electron impact ionization cross section of atomic hydrogen in the metastable 2S state

1975 ◽  
Vol 343 (1634) ◽  
pp. 333-349 ◽  
Keyword(s):  
Electric Field ◽  
Electron Energy ◽  
Cross Section ◽  
Cross Sections ◽  
Ionization Cross Section ◽  
Impact Ionization ◽  
Weak Field ◽  
Weak Electric Field ◽  
Hydrogen Atoms ◽  
Ionization Cross

The total ionization cross section for electrons colliding with metastable 2S atoms has been measured up to 500 eV electron energy by a crossed beam technique. A beam of fast hydrogen atoms, containing about 25% in the 2S state and the rest in the IS ground state, is formed by charge capture onto protons that are passed through a caesium vapour target. Protons emerging from the target are removed from the beam by deflexion in a weak electric field. Atoms formed by capture into long-lived, high quantum states are first ionized in a topographically suitable field and then removed by deflexion in the weak field. The signal arising from electron ionization of the 2S atoms is identified by quenching them in a pulsed electric field. Contributions from other sources of extraneous ionization are eliminated by modulated beam techniques. The cross sections are determined from absolute measurements of the beam fluxes, the geometry of the interaction region and the rate at which 2S atoms are ionized. The results show that as the electron energy is raised, the ionization cross section for 2S atoms rises to a maximum at about 4 times the ionization energy of the 2S state. This maximum, about 10 -15 cm 2 , is 13 times larger than th at of the IS atoms. Comparison with various theoretical determinations indicates th at best agreement is obtained with the Born approximation which includes exchange, but below 100eV the classical Monte Carlo approximation agrees equally well with observations.

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