Relativistic solar cosmic rays

Abstract

This paper reviews the present state of knowledge concerning the relativistic particles of solar origin. The analytic techniques for obtaining information regarding the distribution of particles in the interplanetary space from ground‐based observations are described. The general features of pitch angle anisotropy of high‐energy particles are outlined. The concepts of relativistic particle propagation in the corona and interplanetary space are discussed with special reference to the relevant new ideas that have emerged from studies of energetic particle events. The experimental and theoretical arguments that indicate that particles can be accelerated to high energies by shock waves in the heliomagnetosphere are reviewed. Finally, a brief summary of the well‐established ideas and unsolved problems is presented.