A space radiation test model study
Abstract
Dynamic models of the energetic populations in the outer radiation belts are being developed to better understand the extreme variations of particle flux in response to magnetospheric and solar activity. The study utilizes the SCATHA SC3 high energy electron data, covering energies from 47 keV to 5 MeV with fine pitch angle measurements (3 deg field of view) over the Lshell range of 5.3 to 8.7. Butterfly distributions in the dusk sector signify particle losses due to L shell splitting of the particle drift orbits and the subsequent scattering of the particles from the orbits by the magnetopause. To model the temporal variations and diffusion procsses of the particle populations, the data have been organized into phase space distributions, binned according to altitude (L shell), energy, pitch angle, and time. These distributions can then be mapped to the equator and plotted for fixed first and second adiabatic invariants of the inherent particle motion. A new and efficient method for calculating the third adiabatic invariant using a line integral of the relevant magnetic potential a t the particle mirror points has been developed and is undergoing testing. This method will provide a useful means of displaying the radial diffusion signatures of the outer radiation belts during the more active periods when the L shell parameter is not a good concept due to severe driftshell splitting. The first phase of fitting the energetic electron phasespace distributions with a combined radial and pitchangle diffusion formulation is underway.
 Publication:

Lockheed Missiles and Space Co. Report
 Pub Date:
 March 1986
 Bibcode:
 1986lock.rept.....N
 Keywords:

 Earth Magnetosphere;
 Earth Orbital Environments;
 Energetic Particles;
 Extraterrestrial Radiation;
 Particle Diffusion;
 Particle Motion;
 Radiation Belts;
 Space Plasmas;
 Adiabatic Conditions;
 Bessel Functions;
 Diffusion Coefficient;
 Magnetic Effects;
 Scatha Satellite;
 Scattering;
 Solar Activity;
 Space Radiation