Particle Diffusion in the Solar Corona

Abstract

The configuration of magnetic fields in the corona is discussed in relation to the escape of energetic solar protons into interplanetary space. In particular an assessment is made of the relative importance of diffusion, drift motions and direct field line connections in the distribution of energetic particles in the corona. Observational evidence on particle flux distributions near the earth is related to the question of storage in the corona. The absence of marked anisotropics at late times during impulsive solar events is indicative of storage in interplanetary space rather than in the corona. It is concluded that the geometry of coronal magnetic fields is such as to permit storage of protons in the energy rage 10–100 MeV for several days and that, on occasion, the fields are of such a form as to permit rapid spreading in latitude and longitude and that this, coupled with the stochastic wandering of field lines, can readily account for the observed spread in solar longitude of particles at IAU.