Energetic charged particles in the magnetosphere of Neptune

Journal Article · Thu Dec 14 23:00:00 EST 1989 · Science (Washington, D.C.); (United States)

DOI:https://doi.org/10.1126/science.246.4936.1489· OSTI ID:5452616

Stone, E C; Cummings, A C; Looper, M D; Selesnick, R S ^[1]; Lal, N; McDonald, F B; Trainor, J H ^[2]; Chenette, D L ^[3]

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1. California Institute of Technology, Pasadena (USA)
2. NASA, Greenbelt, MD (USA)
3. Lockheed Palo Alto Research Laboratory, CA (USA)

The Voyager 2 cosmic ray system (CRS) measured significant fluxes of energetic ({approx lt}1 megaelectron volt (MeV)) trapped electrons and protons in the magnetosphere of Neptune. The intensities at maximum near a magnetic L shell of 7, decreasing closer to the planet because of absorption by satellites and rings. In the region of the inner satellites of Neptune, the radiation belts have a complicated structure, which provides some constraints on the magnetic field geometry of the inner magnetosphere. Electron phase-space densities have a positive radial gradient, indicating that they diffuse inward from a source in the outer magnetosphere. Electron spectra from 1 to 5 MeV are generally well represented by power laws with indices near 6, which harden in the region of peak flux to power law indices of 4 to 5. Protons have significantly lower fluxes than electrons throughout the magnetosphere, with large anisotropies due to radial intensity gradients. The radiation belts resemble those of Uranus to the extent allowed by the different locations of the satellites, which limit the flux at each planet.

• OSTI ID: 5452616
• Journal Information: Science (Washington, D.C.); (United States), Journal Name: Science (Washington, D.C.); (United States) Vol. 246:4936; ISSN SCIEA; ISSN 0036-8075
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
BARYONS
ELECTRON SPECTRA
ELECTRONS
ELEMENTARY PARTICLES
FERMIONS
HADRONS
LEPTONS
MAGNETIC FIELDS
MORPHOLOGY
NEPTUNE PLANET
NUCLEONS
PLANETARY ATMOSPHERES
PLANETARY MAGNETOSPHERES
PLANETS
PROTONS
RADIATION BELTS
RINGS
SATELLITES
SPACE VEHICLES
SPECTRA
TRAPPED ELECTRONS
TRAPPED PROTONS
URANUS PLANET
VEHICLES
VOYAGER SPACE PROBES