Global zones of particle precipitation

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:6595566

Miah, M A

Magnetospheric particles are precipitated at low altitude all over the globe. The study of the physics of the equatorial global zone is important for geospace environment modeling, for knowing the loss processes of radiation belt particles and for the Space Station Project. The equatorial global zone was investigated by the Phoenix-1 experiment on board the S81-1 mission in May through November, 1982. The global profile of the peak flux of quasi-trapped protons follows the line of minimum magnetic field strength, with a FWHM of {approximately}13{degree} in latitude. The pitch angle distribution anisotropy index is found to be 19{+-} 2, and the protons show no statistically significant longitude dependence. Contrary to an earlier observation the author finds a strong altitude dependence. Within the altitude range of observation ({approximately}160-285 km) the proton flux varies as the fifth power of altitude. This altitude gradient indicates a strong depletion of source neutrals, coupled with charge exchange loss and ionization loss of protons. A power law fit to the flux values of the previous observations, yields an energy spectral index of {minus}2.55 {+-} 0.11, implying that the mean energy of the protons observed by Phoenix-1 is 1.3 MeV. For comparison of the observed proton population with the earlier observation, the response functions of both instruments - the monitor telescope on the S81-1 mission, and the EI-92 telescope on the Azur mission-have been calculated as a function of the satellite orbital parameters and instrument geometry, both in the dipole and real magnetic field models.

• Research Organization: Louisiana State Univ. and Agricultural and Mechanical Coll., Baton Rouge, LA (USA)
• OSTI ID: 6595566
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALTITUDE
BARYONS
CHARGED-PARTICLE PRECIPITATION
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
ELEMENTARY PARTICLES
FERMIONS
FUNCTIONS
GLOBAL ASPECTS
HADRONS
MATHEMATICAL MODELS
MEASURING INSTRUMENTS
NUCLEONS
PROTON PRECIPITATION
PROTONS
RESPONSE FUNCTIONS
TRAPPED PROTONS