Cosmic-ray solar-flare increase of 28 January 1967

Abstract
The main features of the solar-flare increase in cosmic-ray intensity observed on 28 January 1967 are presented. The flare increase showed no marked anisotropy. It is shown that the onset and decay of this increase can be well accounted for by anisotropic diffusion of particles in a spherically symmetric, inhomogeneous medium with a perfectly absorbing boundary at about 1.3 AU from the sun.