Protons of 0.1 to 5 Mev and electrons of 20 kev at 12 Earth radii during sudden commencement on September 30, 1961

Journal Article · Sat Dec 01 04:00:00 EST 1962 · Journal of Geophysical Research

DOI:https://doi.org/10.1029/JZ067i013p05001· OSTI ID:4733006

Hoffman, R. A.; Davis, L. R.; Williamson, J. M.

During the period around the sudden commencement of the September 30. 1981, magnetic storm, the ion-electron detector aboard Explorer 12 observed fluxes of low-energy protons and electrons while the satellite was at 12 earth radii and free of the magnetosphere. Whereas the proton intensities initiated an increase about 25 minutes before the sudden commencement, a sudden jump in the omnidirectional intensity occurred eight minutes before the sudden commencement. The maximum flux of about 2 x 10⁵ hour after the sudden commencement. Thereafter the intensities varied irregularly with time and displayed fluctuations in anisotropy over the look cone of the detector that were dependent upon the direction of the local magnetic field. The energy spectrum was independent of both time and intensity. The energy density of the proton spectrum (1 x 10^-9 erg/cm³ ) was too small to account for the observed compression of the earth's field on the sunlit side during the magnetic storm. Time coincident with the sudden jump in proton intensities, an electron flux first appeared and reached its peak value of 3 x 10⁶ electrons/cm² sec ster in the 10- to 35-kev range about one minute before the observance of the sudden commencement on the earth's surface. It continued for about 10 minutes and then disappeared. The detection efficiency for electrons places an upper limit of 2 x 10⁵ electrons/cm² sec ster for the rest of the storm.

• Research Organization: Goddard Space Flight Center, Greenbelt, Md.
• Sponsoring Organization: USDOE
• NSA Number: NSA-17-006922
• OSTI ID: 4733006
• Journal Information: Journal of Geophysical Research, Journal Name: Journal of Geophysical Research Journal Issue: 13 Vol. 67; ISSN 0148-0227
• Publisher: American Geophysical Union
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ANISOTROPY
COSMIC RADIATION
DETECTION
DISTRIBUTION
EARTH
EFFICIENCY
ELECTRONS
ENERGY
ENERGY RANGE
EXPLORER SATELLITES
IONS
KEV RANGE
LEVELS
MAGNETIC FIELDS
MEASURED VALUES
MEV RANGE
ORBITS
PROTONS
RADIATION BELTS
SATELLITES
SPACE
SUN
TURBULENCE
VARIATIONS