scholarly journals In situ evidence of the modification of the parallel propagation of EMIC waves by heated He+ ions

2016 ◽  
Vol 121 (7) ◽  
pp. 6711-6717 ◽  
Author(s):  
Zhigang Yuan ◽  
Xiongdong Yu ◽  
Dedong Wang ◽  
Shiyong Huang ◽  
Haimeng Li ◽  
...  
Keyword(s):  
Parallel Propagation ◽  
Emic Waves

scholarly journals Energetic ions scattered into the loss cone with observations of the Cluster satellite

2016 ◽  
Vol 34 (2) ◽  
pp. 249-257 ◽  
Author(s):  
Ying Xiong ◽  
Zhigang Yuan ◽  
Jingfang Wang
Keyword(s):  
Field Line ◽  
Plasma Sheet ◽  
Outer Boundary ◽  
Scattering Mechanism ◽  
Loss Cone ◽  
Energetic Ions ◽  
Left Hand ◽  
Central Plasma ◽  
Emic Waves

Abstract. In this paper, we report in situ observations by the Cluster spacecraft of energetic ions scattered into the loss cone during the inbound pass from the plasma sheet into the plasmasphere. During the inbound pass of the plasma sheet, Cluster observed the isotropy ratio of energetic ions to gradually decrease from unity and the isotropic boundary extended to lower L value for higher-energy ions, implying that the field line curvature scattering mechanism is responsible for the scattered ions into the loss cone from the plasma sheet. In the outer boundary of a plasmasphere plume, Cluster 3 observed the increase of the isotropy ratio of energetic ions accompanied by enhancements of Pc2 waves with frequencies between the He+ ion gyrofrequency and O+ ion gyrofrequency estimated in the equatorial plane. Those Pc2 waves were left-hand circularly polarized and identified as electromagnetic ion cyclotron (EMIC) waves. Using the observed parameters, the calculations of the pitch angle diffusion coefficients for ring current protons demonstrate that EMIC waves could be responsible for the ions scattering and loss-cone filling. Our observations provide in situ evidence of energetic ion loss in the plasma sheet and the plasmasphere plume. Our results suggest that energetic ions scattering into the loss cone in the central plasma sheet and the outer boundary of the plasmaspheric plume are attributed to the field line curvature scattering mechanism and EMIC wave scattering mechanism, respectively.

scholarly journals In situ observations of EMIC waves in O + band by the Van Allen Probe A

2015 ◽  
Vol 42 (5) ◽  
pp. 1312-1317 ◽  
Author(s):  
Xiongdong Yu ◽  
Zhigang Yuan ◽  
Dedong Wang ◽  
Haimeng Li ◽  
Shiyong Huang ◽  
...  
Keyword(s):  
In Situ Observations ◽  
Emic Waves

scholarly journals In situ statistical observations of Pc1 pearl pulsations and unstructured EMIC waves by the Van Allen Probes

2017 ◽  
Vol 122 (1) ◽  
pp. 105-119 ◽  
Author(s):  
K. W. Paulson ◽  
C. W. Smith ◽  
M. R. Lessard ◽  
R. B. Torbert ◽  
C. A. Kletzing ◽  
...  
Keyword(s):  
Van Allen Probes ◽  
Emic Waves

scholarly journals High-resolution in situ observations of electron precipitation-causing EMIC waves

2015 ◽  
Vol 42 (22) ◽  
pp. 9633-9641 ◽  
Author(s):  
Craig J. Rodger ◽  
Aaron T. Hendry ◽  
Mark A. Clilverd ◽  
Craig A. Kletzing ◽  
James B. Brundell ◽  
...  
Keyword(s):  
High Resolution ◽  
Electron Precipitation ◽  
In Situ Observations ◽  
Emic Waves

Rendez vous with Saturn's rings

1984 ◽  
Vol 75 ◽  
pp. 743-759 ◽  
Author(s):  
Kerry T. Nock
Keyword(s):  
Solar Energy ◽  
Electric Propulsion ◽  
Power Source ◽  
Propulsion System ◽  
Low Thrust ◽  
Ring Plane ◽  
The Earth ◽  
Total Impulse ◽  
Saturn's Rings

ABSTRACTA mission to rendezvous with the rings of Saturn is studied with regard to science rationale and instrumentation and engineering feasibility and design. Future detailedin situexploration of the rings of Saturn will require spacecraft systems with enormous propulsive capability. NASA is currently studying the critical technologies for just such a system, called Nuclear Electric Propulsion (NEP). Electric propulsion is the only technology which can effectively provide the required total impulse for this demanding mission. Furthermore, the power source must be nuclear because the solar energy reaching Saturn is only 1% of that at the Earth. An important aspect of this mission is the ability of the low thrust propulsion system to continuously boost the spacecraft above the ring plane as it spirals in toward Saturn, thus enabling scientific measurements of ring particles from only a few kilometers.

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