scholarly journals Direct evidence for EMIC wave scattering of relativistic electrons in space

2016 ◽  
Vol 121 (7) ◽  
pp. 6620-6631 ◽  
Author(s):  
X.-J. Zhang ◽  
W. Li ◽  
Q. Ma ◽  
R. M. Thorne ◽  
V. Angelopoulos ◽  
...  
Keyword(s):  
Wave Scattering ◽  
Direct Evidence ◽  
Relativistic Electrons ◽  
Emic Wave

scholarly journals Loss of geosynchronous relativistic electrons by EMIC wave scattering under quiet geomagnetic conditions

2014 ◽  
Vol 119 (10) ◽  
pp. 8357-8371 ◽  
Author(s):  
K. Hyun ◽  
K.-H. Kim ◽  
E. Lee ◽  
H.-J. Kwon ◽  
D.-H. Lee ◽  
...  
Keyword(s):  
Wave Scattering ◽  
Relativistic Electrons ◽  
Emic Wave

scholarly journals Evidence for Magnetic Fields in the Outflow from T Tau S

1997 ◽  
Vol 182 ◽  
pp. 475-480
Author(s):  
T.P. Ray ◽  
T.W.B. Muxlow ◽  
D.J. Axon ◽  
A. Brown ◽  
D. Corcoran ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Radio Emission ◽  
Direct Evidence ◽  
Relativistic Electrons ◽  
Radio Flux ◽  
Optical Star ◽  
Gyrosynchrotron Emission ◽  
Left And Right ◽  
T Tau ◽  
Opposite Helicity

We have observed at 5GHz the T Tau system with high resolution (≲0″.1) using the Multi-Element Radio Linked Interferometer (MERLIN) based at Jodrell Bank. Both the optical star (T Tau N) and its well-known infrared companion (T Tau S) were detected. The radio emission from T Tau S was found to be roughly extended in the direction of what is thought to be its outflow axis. More importantly we discovered that this radio emission split up into two spatially separated lobes of opposite helicity in the left and right-circular polarization channels. The circularly polarized lobes appear to straddle the star so that the “flow” and the “counterflow” were of opposite helicity. Such observations are the first direct evidence for the presence of magnetic fields in extended outflows that we are aware of. The radio flux appears to be due to gyrosynchrotron emission from mildly relativistic electrons (γ≈2–3). These electrons may have been accelerated in shocks close to the source. Using reasonable assumptions, the inferred magnetic fields strengths are surprisingly large (≳ several gauss) at distances of approximately 10-20 AU from their source. This is consistent with the magnetic fields being part of a collimated flow.

Statistical Dependence of EMIC Wave Scattering on Wave and Plasma Parameters

2020 ◽  
Vol 125 (4) ◽  
Author(s):  
Murong Qin ◽  
Mary Hudson ◽  
Robyn Millan ◽  
Leslie Woodger ◽  
Xiaochen Shen
Keyword(s):  
Wave Scattering ◽  
Statistical Dependence ◽  
Plasma Parameters ◽  
Emic Wave

High-speed stream driven inferences of global wave distributions at geosynchronous orbit: relevance to radiation-belt dynamics

2010 ◽  
Vol 466 (2123) ◽  
pp. 3351-3362 ◽  
Author(s):  
Elizabeth A. MacDonald ◽  
Lauren W. Blum ◽  
S. Peter Gary ◽  
Michelle F. Thomsen ◽  
Michael H. Denton
Keyword(s):  
High Speed ◽  
Radiation Belt ◽  
Recovery Phase ◽  
Wave Activity ◽  
Geosynchronous Orbit ◽  
Relativistic Electrons ◽  
Particle Interactions ◽  
Early Recovery ◽  
Emic Wave ◽  
Major Loss

Three superposed epoch analyses of plasma data from geosynchronous orbit are compared to infer relative distributions of electromagnetic ion cyclotron (EMIC)- and whistler-mode wave instabilities. Both local-time and storm-time behaviours are studied with respect to dynamics of relativistic electrons. Using LANL-GEO particle data and a quasi-linear approximation for the wave growth allows us to estimate the instability of the two wave modes. This simple technique can allow powerful insights into wave–particle interactions at geosynchronous orbit. Whistler-wave activity peaks on the dayside during the early recovery phase and can continue to be above normal levels for several days. The main phase of all storms exhibits the most EMIC-wave activity, whereas in the recovery phase of the most radiation-belt-effective storms, a significantly suppressed level of EMIC activity is inferred. These key results indicate new dynamics relating to plasma delivery, source and response, but support generally accepted views of whistlers as a source process and EMIC-mode waves as a major loss contributor at geosynchronous orbit.

scholarly journals Direct Evidence of the Pitch Angle Scattering of Relativistic Electrons Induced by EMIC Waves

2020 ◽  
Vol 47 (4) ◽  
Author(s):  
Hui Zhu ◽  
Lunjin Chen ◽  
Seth G. Claudepierre ◽  
Liheng Zheng
Keyword(s):  
Pitch Angle ◽  
Direct Evidence ◽  
Relativistic Electrons ◽  
Angle Scattering ◽  
Emic Waves
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