scholarly journals VHF coherent radar signals from theEregion ionosphere and the relationship to electron drift velocity and ion acoustic velocity

2002 ◽  
Vol 107 (A1) ◽  
Author(s):  
E. Nielsen
Keyword(s):  
Drift Velocity ◽  
Acoustic Velocity ◽  
Electron Drift Velocity ◽  
Electron Drift ◽  
Ion Acoustic ◽  
Radar Signals ◽  
Coherent Radar ◽  
The Relationship

scholarly journals The electron drift velocity, ion acoustic speed and irregularity drifts in high-latitude E-region

2008 ◽  
Vol 26 (11) ◽  
pp. 3395-3409 ◽  
Author(s):  
M. V. Uspensky ◽  
R. J. Pellinen ◽  
P. Janhunen
Keyword(s):  
Drift Velocity ◽  
Equatorial Electrojet ◽  
Electron Drift Velocity ◽  
Doppler Velocity ◽  
Electron Drift ◽  
Velocity Dependence ◽  
Flow Angle ◽  
Aspect Angle ◽  
Ion Acoustic ◽  
Acoustic Speed

Abstract. The purpose of this study is to examine the STARE irregularity drift velocity dependence on the EISCAT line-of-sight (los or l-o-s) electron drift velocity magnitude, VE×Blos, and the flow angle ΘN,F (superscript N and/or F refer to the STARE Norway and Finland radar). In the noon-evening sector the flow angle dependence of Doppler velocities, VirrN,F, inside and outside the Farley-Buneman (FB) instability cone (|VE×Blos|>Cs and |VE×Blos|<Cs, respectively, where Cs is the ion acoustic speed), is found to be similar and much weaker than suggested earlier. In a band of flow angles 45°<ΘN,F<85° it can be reasonably described by |VirrN,F|∝AN,FCscosnΘN,F, where AN,F≈1.2–1.3 are monotonically increasing functions of VE×B and the index n is ~0.2 or even smaller. This study (a) does not support the conclusion by Nielsen and Schlegel (1985), Nielsen et al. (2002, their #[18]) that at flow angles larger than ~60° (or |VirrN,F|≤300 m/s) the STARE Doppler velocities are equal to the component of the electron drift velocity. We found (b) that if the data points are averages over 100 m/s intervals (bins) of l-o-s electron velocities and 10 deg intervals (bins) of flow angles, then the largest STARE Doppler velocities always reside inside the bin with the largest flow angle. In the flow angle bin 80° the STARE Doppler velocity is larger than its driver term, i.e. the EISCAT l-o-s electron drift velocity component, |VirrN,F|>|VE×Blos|. Both features (a and b) as well as the weak flow angle velocity dependence indicate that the l-o-s electron drift velocity cannot be the sole factor which controls the motion of the backscatter ~1-m irregularities at large flow angles. Importantly, the backscatter was collected at aspect angle ~1° and flow angle Θ>60°, where linear fluid and kinetic theories invariably predict negative growth rates. At least qualitatively, all the facts can be reasonably explained by nonlinear wave-wave coupling found and described by Kudeki and Farley (1989), Lu et al. (2008) for the equatorial electrojet and studied in numerical simulation by Otani and Oppenheim (1998, 2006).

Electron drift velocity versus electric field in GaAs

1986 ◽  
Vol 29 (12) ◽  
pp. 1295-1296 ◽  
Author(s):  
Chian S. Chang ◽  
Harold R. Fetterman
Keyword(s):  
Electric Field ◽  
Drift Velocity ◽  
Electron Drift Velocity ◽  
Velocity Versus ◽  
Electron Drift

Electron Drift-Velocity Detector for Gas Chromatography.

1964 ◽  
Vol 36 (9) ◽  
pp. 1739-1744 ◽  
Author(s):  
V. N. Smith ◽  
J. F. Fidiam
Keyword(s):  
Gas Chromatography ◽  
Drift Velocity ◽  
Electron Drift Velocity ◽  
Electron Drift

scholarly journals Увеличение насыщенной скорости дрейфа электронов в pHEMT-гетероструктурах с донорно-акцепторным легированием

2018 ◽  
Vol 44 (6) ◽  
pp. 77
Author(s):  
Д.Ю. Протасов ◽  
Д.В. Гуляев ◽  
А.К. Бакаров ◽  
А.И. Торопов ◽  
Е.В. Ерофеев ◽  
...  
Keyword(s):  
Drift Velocity ◽  
High Electron Mobility Transistor ◽  
Real Space ◽  
Electron Drift Velocity ◽  
Hot Electrons ◽  
Electron Drift ◽  
High Electron ◽  
High Electron Mobility ◽  
Donor Acceptor ◽  
Real Space Transfer

AbstractField dependences of the electron-drift velocity in typical pseudomorphic high-electron-mobility transistor (pHEMT) heteroepitaxial structures (HESs) and in those with donor–acceptor doped (DApHEMT) heterostructures with quantum-well (QW) depth increased by 0.8–0.9 eV with the aid of acceptor layers have been studied by a pulsed technique. It is established that the saturated electron-drift velocity in DA-pHEMT-HESs is 1.2–1.3 times greater than that in the usual pHEMT-HESs. The electroluminescence (EL) spectra of DA-pHEMT-HESs do not contain emission bands related to the recombination in widebandgap layers (QW barriers). The EL intensity in these HESs is not saturated with increasing electric field. This is indicative of a suppressed real-space transfer of hot electrons from QW to barrier layers, which accounts for the observed increase in the saturated electron-drift velocity.

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