Relativistic electrons in Saturn's inner magnetosphere and an estimate of their synchrotron emission. Progress report

Technical Report · Sat Jul 01 04:00:00 EDT 1989

OSTI ID:5439974

Van Allen, J A; Grosskreutz, C L

Energetic electron data obtained during Pioneer 11's two-way traversal of Saturn's inner magnetosphere in September 1979 are reviewed. There were substantial differences between inbound and outbound observations. The inbound data are more likely to represent the time-stationary state. A quantitative model is made for the spatial and spectral distributions of relativistic electrons. The principal features of this model are as follows: (1) The radial dependence of omnidirectional intensity J in the equatorial plane is given by J = k' exp(-1.05 x)1-EXP(-6.5 X). This distribution is applicable to the range 2.30 < or = r < or = 3.60. (2) The latitudinal dependence of J is derived from observed pitch-angle distributions. (3) As shown previously, the energy spectrum is a relatively narrow one with characteristic energies E in MeV at various r as follows: 0.69 at 5.0; 1.10 at 4.0; 1.89 at 3.0; 2.62 at 2.5; and 3.05 at 2.30. The synchrotron emission of the entire population of relativistic electrons in Saturn's inner magnetosphere is estimated to be about 1 kW with a spectral maximum at 720 kHz. It is shown that this radiation will be very difficult, if not impossible, to observe even in the near vicinity of the planet. This paper includes a crude but instructive explication of the truly enormous differences between the synchrotron emissions of the inner magnetospheres of Jupiter and Saturn. Indeed, this comparison was an underlying motive for undertaking the present day.

• Research Organization: Iowa Univ., Iowa City, IA (USA). Dept. of Physics and Astronomy
• OSTI ID: 5439974
• Report Number(s): AD-A-211448/6/XAB
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics &amp; Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
BREMSSTRAHLUNG
DISTRIBUTION
DOCUMENT TYPES
ELECTROMAGNETIC RADIATION
ELECTRON EMISSION
ELECTRONS
ELEMENTARY PARTICLES
EMISSION
ENERGY RANGE
ENERGY SPECTRA
FERMIONS
LEPTONS
PIONEER SPACE PROBES
PLANETARY ATMOSPHERES
PLANETARY MAGNETOSPHERES
PLANETS
PROGRESS REPORT
RADIATIONS
RELATIVISTIC RANGE
SATURN PLANET
SPACE VEHICLES
SPATIAL DISTRIBUTION
SPECTRA
SYNCHROTRON RADIATION
VEHICLES