Pitch angle distributions of solar energetic particles and the local scattering properties of the interplanetary magnetic field
Abstract
An approximate solution of the FokkerPlanck equation containing pitch angle scattering and adiabatic focusing is discussed. For modest focusing effects the omnidirectional density obeys an ordinary diffusion equation with a modified diffusion coefficient. The anisotropic part of the distribution function is properly normalized and split into an even and an odd part. The even part is determined by the ratio between the scattering mean free path and the focusing length and by the degree of polarization of the magnetic field fluctuations. The odd part is determined by the deviation of the pitch angle scattering from isotropic scattering. The method supplies a powerful tool to obtain the local characteristics of pitch angle scattering. It is insensitive to long lasting solar injections and to moderate radial variations of the mean free path. The method is applied to solar particle events observed on Helio1 and 2.
 Publication:

19th International Cosmic Ray Conference (ICRC19), Volume 4
 Pub Date:
 August 1985
 Bibcode:
 1985ICRC....4Q.335B
 Keywords:

 Distribution (Property);
 FokkerPlanck Equation;
 Interplanetary Magnetic Fields;
 Solar Cosmic Rays;
 Cosmic Ray Showers;
 Helios 1;
 Helios 2;
 Magnetic Field Configurations;
 Propagation;
 Scattering;
 Solar Physics