Auroral‐enhanced Plasma Lines by Suprathermal Electrons Observed by EISCAT

2021 ◽  
Author(s):  
Ting Feng ◽  
Moran Liu ◽  
Bin Xu ◽  
Tong Xu ◽  
Shuaihe Gao ◽  
...  
Keyword(s):  
Suprathermal Electrons

scholarly journals Some Anomalies in the Raman spectrum from laser-produced plasmas

1988 ◽  
Vol 6 (2) ◽  
pp. 287-294
Author(s):  
T. J. M. Boyd ◽  
G. A. Gardner ◽  
G. A. Coutts
Keyword(s):  
Raman Spectrum ◽  
Light Wave ◽  
Scattered Light ◽  
Thomson Scattering ◽  
Hot Electron ◽  
Conventional Theory ◽  
Suprathermal Electron ◽  
Suprathermal Electrons ◽  
Scattered Spectrum

Many experiments show features of the Raman spectrum at variance with the predictions of conventional theory. One persistent discrepancy, the cut-off in the spectrum of scattered light at about 1·5λ0, led Simon and Short to postulate that the scattered spectrum is not Raman light as such, but derives from enhanced Thomson scattering from plasmas in which a population of suprathermal electrons is present. We describe a set of simulations which model the propagation of a light wave through a plasma characterized by two electron temperatures with the hot electron fraction varying between 0 and 0·05. The results show that enhanced Thomson scattering will contribute to the spectra observed in some experiments at least and confirm the contention that the spectrum of the scattered light is not especially sensitive to the width of the suprathermal electron feature. We have also examined the effect of a finite quiver velocity on the enhanced Thomson spectrum as a function of the population of suprathermal electrons, in particular its effect on the wavelength bands.

scholarly journals Electron beam—plasma interaction in a dusty plasma with excess suprathermal electrons

2011 ◽  
Author(s):  
A. Danehkar ◽  
N. S. Saini ◽  
M. A. Hellberg ◽  
I. Kourakis ◽  
Vladimir Yu. Nosenko ◽  
...  
Keyword(s):  
Electron Beam ◽  
Dusty Plasma ◽  
Plasma Interaction ◽  
Suprathermal Electrons ◽  
Beam Plasma ◽  
Electron Beam Plasma

scholarly journals Plasma properties of suprathermal electrons near comet 67P/Churyumov-Gerasimenko with Rosetta

2019 ◽  
Vol 630 ◽  
pp. A42 ◽  
Author(s):  
M. Myllys ◽  
P. Henri ◽  
M. Galand ◽  
K. L. Heritier ◽  
N. Gilet ◽  
...  
Keyword(s):  
Solar Wind ◽  
Heliocentric Distance ◽  
Radial Distance ◽  
Hot Electron ◽  
Plasma Properties ◽  
Measured Velocity ◽  
Electron Population ◽  
Suprathermal Electrons ◽  
Comet 67P ◽  
Cometary Activity

Context. The Rosetta spacecraft escorted comet 67P/Churyumov-Gerasimenko from 2014 to September 2016. The mission provided in situ observations of the cometary plasma during different phases of the cometary activity, which enabled us to better understand its evolution as a function of heliocentric distance. Aims. In this study, different electron populations, called warm and hot, observed by the Ion and Electron Sensor (IES) of the Rosetta Plasma Consortium (RPC) are investigated near the comet during the escorting phase of the Rosetta mission. Methods. The estimates for the suprathermal electron densities and temperatures were extracted using IES electron data by fitting a double-kappa function to the measured velocity distributions. The fitting results were validated using observations from other RPC instruments. We give upgraded estimates for the warm and hot population densities compared to values previously shown in literature. Results. The fitted density and temperature estimates for both electron populations seen by IES are expressed as a function of heliocentric distance to study their evolution with the cometary activity. In addition, we studied the dependence between the electron properties and cometocentric distance. Conclusions. We observed that when the neutral outgassing rate of the nucleus is high (i.e., near perihelion) the suprathermal electrons are well characterized by a double-kappa distribution. In addition, warm and hot populations show a significant dependence with the heliocentric distance. The populations become clearly denser near perihelion while their temperatures are observed to remain almost constant. Moreover, the warm electron population density is shown to be strongly dependent on the radial distance from the comet. Finally, based on our results we reject the hypothesis that hot electron population seen by IES consists of solely suprathermal (halo) solar wind electrons, while we suggest that the hot electron population mainly consists of solar wind thermal electrons that have undergone acceleration near the comet.

Global distributions of suprathermal electrons observed on THEMIS and potential mechanisms for access into the plasmasphere

2010 ◽  
Vol 115 (A12) ◽  
pp. n/a-n/a ◽  
Author(s):  
W. Li ◽  
R. M. Thorne ◽  
J. Bortnik ◽  
Y. Nishimura ◽  
V. Angelopoulos ◽  
...  
Keyword(s):  
Suprathermal Electrons
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