THE ALBEDO NEUTRON THEORY OF GEOMAGNETICALLY TRAPPED PROTONS

Journal Article · Tue Oct 01 04:00:00 EDT 1963 · Planetary Space Sci.

DOI:https://doi.org/10.1016/0032-0633(63)90251-4· OSTI ID:4151555

Lenchek, A M; Singer, S F

The neutron albedo theory of geomagnetically trapped protons is reviewed. The intensity, energy spectrum, andd angular distribution of fast albedo neutrons emerging from the atmosphere is investigated. Two components may be distinguished: global neutrons that are generated by atmospheric interactions of galactic cosmic rays and polar neutrons that are generated by solar cosmic rays. Each class of neutrons produces a component of trapped protons with distinctive characteristics. The spatial distribution of decaying neutrons in the global component is quite uniform with respect to altitude and pitch angle over the inner belt, varying only very slowly ss compared to the variation of loss rates or lifetimes. The latter were studied for the relevant collision processes. For fast protons the important process is ionization loss in Coulomb interactions. At very high energy absorption in nonelastic nuclear collisions is impontant. At energies below approximates 1 Mev charge exchange is impontant. The lifetimes at low altitudes are therefore governed by the exospheric density. At high altitudes the lifetimes are limited by a breakdown of the trapping condition. The result is a broad belt of high energy protons centered on the magnetic equator with a peak intensity at L approximates 1.5 Earth radii. The polar neutrons generate a proton distribution with quite different characteristics. The mean energy is lower. The saptial distribution has a sharp inner boundary near L = 1.6 and has a minimum intensity in the magnetic equatorial plane. The polar component overlaps the global component and extends to considerably higher altitude. (auth)

• Research Organization: Univ. of Maryland, College Park
• NSA Number: NSA-18-002743
• OSTI ID: 4151555
• Journal Information: Planetary Space Sci., Journal Name: Planetary Space Sci. Vol. Vol: 11
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ABSORPTION
ALBEDO
ANGULAR DISTRIBUTION
ATMOSPHERE
CHARGED PARTICLES
CONFIGURATION
COSMIC RADIATION
DECAY
DENSITY
DISTRIBUTION
EARTH
ENERGY
FAST NEUTRONS
INTERACTIONS
IONIZATION
LEVELS
LIFETIME
LOSSES
MAGNETIC FIELDS
NEUTRONS
NUCLEI
PHYSICS
PRODUCTION
PROTONS
QUANTITY RATIO
RADIATION BELTS
REFLECTION
SPACE
SPECTRA
SUN
VARIATIONS