Signature of a Parallel Electric Field in Ion and Electron Distributions in Velocity Space.

1978 ◽  
Author(s):  
Donald R. Croley ◽  
Mizera Jr. ◽  
Fennell Paul F. ◽  
Joseph F.
Keyword(s):  
Electric Field ◽  
Velocity Space ◽  
Parallel Electric Field ◽  
Electron Distributions

scholarly journals Diagnosing collisionless energy transfer using field–particle correlations: Alfvén-ion cyclotron turbulence

2020 ◽  
Vol 86 (4) ◽  
Author(s):  
Kristopher G. Klein ◽  
Gregory G. Howes ◽  
Jason M. TenBarge ◽  
Francesco Valentini
Keyword(s):  
Energy Transfer ◽  
Electric Field ◽  
Transfer Rate ◽  
Velocity Space ◽  
Turbulence Energy ◽  
Correlation Technique ◽  
Parallel Electric Field ◽  
Particle Correlation ◽  
Particle Correlations ◽  
Ion Cyclotron

We apply field–particle correlations – a technique that tracks the time-averaged velocity-space structure of the energy density transfer rate between electromagnetic fields and plasma particles – to data drawn from a hybrid Vlasov–Maxwell simulation of Alfvén-ion cyclotron turbulence. Energy transfer in this system is expected to include both Landau and cyclotron wave–particle resonances, unlike previous systems to which the field–particle correlation technique has been applied. In this simulation, the energy transfer rate mediated by the parallel electric field $E_{\Vert }$ comprises approximately 60 % of the total rate, with the remainder mediated by the perpendicular electric field $E_{\bot }$ . The parallel electric field resonantly couples to protons, with the canonical bipolar velocity-space signature of Landau damping identified at many points throughout the simulation. The energy transfer mediated by $E_{\bot }$ preferentially couples to particles with $v_{tp}\lesssim v_{\bot }\lesssim 3v_{tp}$ , where $v_{tp}$ is the proton thermal speed, in agreement with the expected formation of a cyclotron diffusion plateau. Our results demonstrate clearly that the field–particle correlation technique can distinguish distinct channels of energy transfer using single-point measurements, even at points in which multiple channels act simultaneously, and can be used to determine quantitatively the rates of particle energization in each channel.

scholarly journals Double layers in the downward current region of the aurora

2003 ◽  
Vol 10 (1/2) ◽  
pp. 45-52 ◽  
Author(s):  
R. E. Ergun ◽  
L. Andersson ◽  
C. W. Carlson ◽  
D. L. Newman ◽  
M. V. Goldman
Keyword(s):  
Magnetic Field ◽  
Electron Beam ◽  
Phase Space ◽  
Electric Field ◽  
Electric Fields ◽  
Double Layers ◽  
Parallel Electric Field ◽  
Electrostatic Waves ◽  
Current Region ◽  
Decisive Evidence

Abstract. Direct observations of magnetic-field-aligned (parallel) electric fields in the downward current region of the aurora provide decisive evidence of naturally occurring double layers. We report measurements of parallel electric fields, electron fluxes and ion fluxes related to double layers that are responsible for particle acceleration. The observations suggest that parallel electric fields organize into a structure of three distinct, narrowly-confined regions along the magnetic field (B). In the "ramp" region, the measured parallel electric field forms a nearly-monotonic potential ramp that is localized to ~ 10 Debye lengths along B. The ramp is moving parallel to B at the ion acoustic speed (vs) and in the same direction as the accelerated electrons. On the high-potential side of the ramp, in the "beam" region, an unstable electron beam is seen for roughly another 10 Debye lengths along B. The electron beam is rapidly stabilized by intense electrostatic waves and nonlinear structures interpreted as electron phase-space holes. The "wave" region is physically separated from the ramp by the beam region. Numerical simulations reproduce a similar ramp structure, beam region, electrostatic turbulence region and plasma characteristics as seen in the observations. These results suggest that large double layers can account for the parallel electric field in the downward current region and that intense electrostatic turbulence rapidly stabilizes the accelerated electron distributions. These results also demonstrate that parallel electric fields are directly associated with the generation of large-amplitude electron phase-space holes and plasma waves.

Effect of the electric field on the agyrotropic electron distributions

2021 ◽  
Author(s):  
C. ‐H. Gao ◽  
B. ‐B. Tang ◽  
W. Y. Li ◽  
C. Wang ◽  
Yu. V. Khotyaintsev ◽  
...  
Keyword(s):  
Electric Field ◽  
Electron Distributions

Relationship between Field-Aligned Currents and Parallel Electric Field Observed by Akebono

1998 ◽  
pp. 59-62 ◽  
Author(s):  
M. Morooka ◽  
T. Yamamoto ◽  
T. Mukai ◽  
K. Tsuruda ◽  
H. Hayakawa ◽  
...  
Keyword(s):  
Electric Field ◽  
Parallel Electric Field

The effect of parallel electric field in shock waves on the acceleration of relativistic ions, electrons, and positrons

2009 ◽  
Vol 16 (11) ◽  
pp. 112308 ◽  
Author(s):  
Seiichi Takahashi ◽  
Hiromasa Kawai ◽  
Yukiharu Ohsawa ◽  
Shunsuke Usami ◽  
Charles Chiu ◽  
...  
Keyword(s):  
Shock Waves ◽  
Electric Field ◽  
Parallel Electric Field ◽  
Electrons And Positrons
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