scholarly journals On the Magnetospheres of Jupiter, Saturn, and Uranus

1977 ◽  
Vol 4 (1) ◽  
pp. 195-224 ◽  
Author(s):  
James A. van Allen
Keyword(s):  
Diffusion Coefficients ◽  
Radiation Belt ◽  
Outer Edge ◽  
Wind Flow ◽  
Radio Emissions ◽  
Solar Wind Flow ◽  
In Situ Observations ◽  
Pioneer 10

A brief descriptive summary of Jupiter’s magnetosphere is based on in situ observations with the spacecraft Pioneer 10 and Pioneer 11 in November-December 1973 and November-December 1974, respectively. Current interpretative work emphasizes particle acceleration and loss mechanisms, the determination of diffusion coefficients by satellite effects, the topology of the outer magnetosphere, the possible recirculation of energetic particles, and the controversial evidence for an extended magnetotail.Available evidence on non-thermal radio emissions of the planet and on the solar wind flow at 10 AU is invoked to suggest that Saturn very likely has a large, well developed magnetosphere resembling that of Jupiter but with the important difference that a radiation belt can not exist interior to the outer edge of the A ring of particulate matter. The first in situ observations will be made by Pioneer 11 in August-September 1979.

Genesis On-board Determination of the Solar Wind Flow Regime

2003 ◽  
pp. 153-171 ◽  
Author(s):  
M. Neugebauer ◽  
J. T. Steinberg ◽  
R. L. Tokar ◽  
B. L. Barraclough ◽  
E. E. Dors ◽  
...  
Keyword(s):  
Solar Wind ◽  
Flow Regime ◽  
Wind Flow ◽  
Solar Wind Flow

scholarly journals MHD effects of the solar wind flow around planets

2000 ◽  
Vol 7 (3/4) ◽  
pp. 201-210 ◽  
Author(s):  
H. K. Biernat ◽  
N. V. Erkaev ◽  
C. J. Farrugia ◽  
D. F. Vogl ◽  
W. Schaffenberger
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Mach Number ◽  
Boundary Conditions ◽  
Wind Flow ◽  
Magnetic Shear ◽  
Thermal Anisotropy ◽  
Terrestrial Magnetosphere ◽  
Solar Wind Flow

Abstract. The study of the interaction of the solar wind with magnetized and unmagnetized planets forms a central topic of space research. Focussing on planetary magnetosheaths, we review some major developments in this field. Magnetosheath structures depend crucially on the orientation of the interplanetary magnetic field, the solar wind Alfvén Mach number, the shape of the obstacle (axisymmetric/non-axisymmetric, etc.), the boundary conditions at the magnetopause (low/high magnetic shear), and the degree of thermal anisotropy of the plasma. We illustrate the cases of Earth, Jupiter and Venus. The terrestrial magnetosphere is axisymmetric and has been probed in-situ by many spacecraft. Jupiter's magnetosphere is highly non-axisymmetric. Furthermore, we study magnetohydrodynamic effects in the Venus magnetosheath.

Chronopotentiometric diffusion coefficients of silver(I) in molten KNO3-Ba(NO3)2 eutectic

1974 ◽  
Vol 27 (7) ◽  
pp. 1559 ◽  
Author(s):  
NP Bansal
Keyword(s):  
Diffusion Process ◽  
Temperature Variation ◽  
Diffusion Coefficients ◽  
Single Step ◽  
Electron Process

The application of chronopotentiometry as an electroanalytical technique for the in situ determination of silver(1) in molten KNO3-Ba(NO3)2 (87.6 : 12.4 mole%) eutectic has been described. Reduction of silver(1) on platinum microelectrode is found to be a reversible, single-step one-electron process. Diffusion coefficients, D (cm2 s-l), of silver(1) in the melt have been determined and its temperature variation in the range 578-697 K could be expressed by the relation (R = 8.314 J K-1 mol-1): D = 0.913 x 10-3 exp(-19810/RT) Effect of the presence of the divalent Ba2+ cations in the fluid on the diffusion process has been discussed.

In situ Investigation of Field and Temperature Effects on the Surface of Metal Tips

1977 ◽  
Vol 35 ◽  
pp. 100-101
Author(s):  
C. Colliex ◽  
P. Sudraud ◽  
J. Van de Walle
Keyword(s):  
Field Ionization ◽  
Accurate Information ◽  
Scanning Microscope ◽  
High Brightness ◽  
Fundamental Parameters ◽  
In Situ Investigation ◽  
Crystallographic Structures ◽  
In Situ Observations

For the achievement of high brightness ion sources, field evaporation, desorption and ionization effects constitute very attractive solutions (1,2). All theses mechanisms are promoted in a very small area on the apex of metal tips. The interpretation of field ionization images is often made uncertain because of the lack of accurate information concerning the topography and the crystallographic structures of the emitter.Several authors (3,4,5) have associated electron microscope visualization of tungsten tips either with CTEM (at standard or high voltages) or with SEM, with the study of field emission or ionization patterns. But very few of these works have coupled these observations to the determination of the fundamental parameters (electric field, tip temperature) which control the emission. For instance, in the scanning microscope, the thermally emitted electrons disturb heavily the working conditions preventing from dynamic in-situ observations.

scholarly journals A statistical study over Europe of the relative locations of lightning and associated energetic burst of electrons from the radiation belt

2016 ◽  
Vol 34 (1) ◽  
pp. 157-164 ◽  
Author(s):  
F. Bourriez ◽  
J.-A. Sauvaud ◽  
J.-L. Pinçon ◽  
J.-J. Berthelier ◽  
M. Parrot
Keyword(s):  
Radiation Belt ◽  
Statistical Study ◽  
Arrival Time ◽  
Lightning Discharge ◽  
Electron Interaction ◽  
Lightning Detection ◽  
In Situ Observations ◽  
Electro Magnetic ◽  
The Uk

Abstract. The DEMETER (Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions) spacecraft detects short bursts of lightning-induced electron precipitation (LEP) simultaneously with newly injected upgoing whistlers. The LEP occurs within < 1 s of the causative lightning discharge. First in situ observations of the size and location of the region affected by the LEP precipitation are presented on the basis of a statistical study made over Europe using the DEMETER energetic particle detector, wave electric field experiment, and networks of lightning detection (Météorage, the UK Met Office Arrival Time Difference network (ATDnet), and the World Wide Lightning Location Network (WWLLN)). The LEP is shown to occur significantly north of the initial lightning and extends over some 1000 km on each side of the longitude of the lightning. In agreement with models of electron interaction with obliquely propagating lightning-generated whistlers, the distance from the LEP to the lightning decreases as lightning proceed to higher latitudes.

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