Energetic-Particle Populations and Cosmic-Ray Entry.
Abstract
This report constitutes a review of recent progress in the study of charged-particle access, transport, and loss with respect to the earth's magnetosphere. A major objective of studying particle access is to identify the sources of trapped and quasi-trapped radiation. Important progress in this area involves the measurement of comparative ionic abundances in the radiation belts. The historic problem of accounting for cosmic-ray cut-off latitudes as a function of particle energy is being solved by the adoption of increasingly realistic and accurate models of the magnetospheric B field. Progress in the estimation of particle-transport coefficients (mainly diffusion coefficients) involves the measurement of fluctuating electric and magnetic fields on the ground, at balloon altitudes, and in space. The importance of particle interactions with discrete waveforms (as distinguished from broad-banded spectral noise) is increasingly being recognized. For example, the unsteady magnetospheric convection associated with substorms contributes importantly to radial diffusion, whereas cyclotron resonance with chorus elements and other discrete excitations may contribute importantly to pitch-angle diffusion and (thus) to the loss of energetic particles from the magnetosphere. The role of man-made signals such as radio transmissions and power-line harmonics in this latter process remains uncertain and continues to be debated. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 17, 1981
- Accession Number
- ADA096970
Entities
People
- Michael Schulz
Organizations
- The Aerospace Corporation