Particle Lifetimes in Strong Diffusion.
Abstract
The mean lifetime tau of a particle distribution, driven to isotropy by intense pitch-angle diffusion, is calculated by analytical means for conditions applicable to the earth's magnetosphere. The resulting algebraic expressions reduce to tau approximately = (64La/35v((alpha sub c)squared)(1-eta)) in the limit of a small equatorial loss cone (half-angle alpha sub c), where v is the particle speed, L is the magnetic shell parameter, a is the radius of the earth, and eta is the particle albedo from the atmosphere at either foot of the field line. Distinction is made in the full expressions for tau between complete isotropy (caused by strong pitch-angle diffusion all along the field line) and incomplete isotropy (caused by strong diffusion that is localized at the magnetic equator) over the upward hemisphere in velocity space. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 31, 1974
- Accession Number
- AD0777576
Entities
People
- Michael Schulz
Organizations
- The Aerospace Corporation