Noncorrelation of ``Anomalous'' Plasma Transport, Equilibrium Plasma Density, and Low-Frequency Potential Oscillations in a Q-Device

1967 ◽  
Vol 10 (11) ◽  
pp. 2442 ◽  
Author(s):  
John A. Decker
Keyword(s):  
Plasma Density ◽  
Low Frequency ◽  
Plasma Transport ◽  
Potential Oscillations ◽  
Equilibrium Plasma

An approximate quantitative analysis of non-equilibrium plasma transport for high density plasmas

1995 ◽  
Vol 16 (S1) ◽  
pp. S19-S42 ◽  
Author(s):  
D. C. Schram ◽  
J. C. M. de Haas ◽  
J. A. M. van der Mullen ◽  
M. C. M. van de Sanden
Keyword(s):  
Quantitative Analysis ◽  
High Density ◽  
Plasma Transport ◽  
Equilibrium Plasma ◽  
Non Equilibrium

scholarly journals Frequency and plasma condition dependent spatial structure of low frequency global potential oscillations in the TJ-II stellarator

2019 ◽  
Vol 59 (4) ◽  
pp. 044006 ◽  
Author(s):  
T. Kobayashi ◽  
U. Losada ◽  
B. Liu ◽  
T. Estrada ◽  
B.Ph. van Milligen ◽  
...  
Keyword(s):  
Spatial Structure ◽  
Low Frequency ◽  
Plasma Condition ◽  
Potential Oscillations

scholarly journals Variations of Helicon Wave-induced Radial Plasma Transport in Different Experimental Conditions

1994 ◽  
Vol 47 (3) ◽  
pp. 315 ◽  
Author(s):  
V Petržílka
Keyword(s):  
Plasma Density ◽  
Plasma Transport ◽  
Plasma Confinement ◽  
Experimental Conditions ◽  
Magnetostatic Field ◽  
Directed Transport ◽  
Helicon Wave ◽  
Transport Velocity ◽  
Plasma Radius ◽  
Wave Induced

Variations of the helicon wave-induced radial plasma transport are presented depending on values of the plasma radius, magnetostatic field, plasma density and the frequency of the helicon wave. It is shown that the value of the helicon wave-induced transport may be significant for plasma confinement; this is demonstrated, for the experiments BASIL and SHEILA. Whereas m = +1 helicons induce an inward-directed transport and thus improve the confinement, m = -1 helicons induce an outward-directed transport velocity.

scholarly journals Space-time evolution of electron-beam driven electron holes and their effects on the plasma

2003 ◽  
Vol 10 (1/2) ◽  
pp. 53-63 ◽  
Author(s):  
N. Singh
Keyword(s):  
Electron Beam ◽  
Plasma Density ◽  
Three Dimensional ◽  
Low Frequency ◽  
Velocity Distribution Function ◽  
Lower Hybrid ◽  
Particle In Cell ◽  
Short Transverse ◽  
Electron Holes ◽  
Number Of Electron Holes

Abstract. We report here further results from the three-dimensional particle-in-cell simulations of the electron-beam driven electron holes. We focus here on (i) the transformation of oscillatory waves driven by the electron-beam instability into electron holes, (ii) the continued evolution and propagation of electron holes after their formation, including merging of electron holes, and (iii) the effects of the evolution on the plasma density and ion velocity distribution function. We find that initially electron-beam modes with perpendicular wave numbers k^ = 0 and as well as k^ ≠ 0 are driven resonantly below the electron plasma frequency of the target plasma. The modes interact nonlinearly and modulate each other both in space and time, producing wave structures with finite perpendicular scale lengths. Nonlinear evolution of such wave structures generates the electron holes in the simulations. Initially, a large number of electron holes form in the plasma. Their merging yields continuously a decreasing number of electron holes. The propagation velocity of the electron holes evolves dynamically and is affected by their merging. At late times only a few electron holes are left in the simulation and they decay by emitting low-frequency electrostatic whistler waves just above the lower hybrid (LH) frequency vlh . These waves, which are long structures parallel to the ambient magnetic field B0 and quite short transverse to B0, are associated with similar structures in the plasma density, producing density filaments. It turns out that electron-beam driven plasmas, in general, develop such filaments at some stage of the evolution of the beam-driven waves. In view of the excitation of the LH waves near vlh, which could resonate with the ions, an analysis shows that it is possible to heat transversely the ions in a time scale of a few seconds in the auroral return current plasma, in which electron holes and transversely heated ions have been simultaneously observed.

scholarly journals Van Allen Probes observation of plasmaspheric hiss modulated by injected energetic electrons

2018 ◽  
Vol 36 (3) ◽  
pp. 781-791 ◽  
Author(s):  
Run Shi ◽  
Wen Li ◽  
Qianli Ma ◽  
Seth G. Claudepierre ◽  
Craig A. Kletzing ◽  
...  
Keyword(s):  
Plasma Density ◽  
Direct Evidence ◽  
Electron Flux ◽  
Energetic Electron ◽  
Low Frequency ◽  
Wave Intensity ◽  
Electron Population ◽  
Ulf Wave ◽  
Van Allen Probes ◽  
First Time

Abstract. Plasmaspheric hiss was observed by Van Allen Probe B in association with energetic electron injections in the outer plasmasphere. The energy of injected electrons coincides with the minimum resonant energy calculated for the observed hiss wave frequency. Interestingly, the variations in hiss wave intensity, electron flux and ultra low frequency (ULF) wave intensity exhibit remarkable correlations, while plasma density is not correlated with any of these parameters. Our study provides direct evidence for the first time that the injected anisotropic electron population, which is modulated by ULF waves, modulates the hiss intensity in the outer plasmasphere. This also implies that the plasmaspheric hiss observed by Van Allen Probe B in the outer plasmasphere (L > ∼ 5.5) is locally amplified. Meanwhile, Van Allen Probe A observed hiss emission at lower L shells (< 5), which was not associated with electron injections but primarily modulated by the plasma density. The features observed by Van Allen Probe A suggest that the observed hiss deep inside the plasmasphere may have propagated from higher L shells.

scholarly journals Excitation of extremely low-frequency chorus emissions: The role of background plasma density

2019 ◽  
Vol 3 (1) ◽  
pp. 1-7 ◽  
Author(s):  
XiongDong Yu ◽  
◽  
ZhiGang Yuan ◽  
ShiYong Huang ◽  
Fei Yao ◽  
...  
Keyword(s):  
Plasma Density ◽  
Low Frequency ◽  
Background Plasma ◽  
Extremely Low Frequency
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