Solar Energetic Particles

In this brief review, we summarize the current state of knowledge of solar energetic particles. This includes energetic particles contained within the site of solar flares that are responsible for X-ray, γ-ray and neutron emission and particles accelerated at high coronal altitudes and in interplanetary space by travelling disturbances such as coronal mass ejections. Special emphasis is placed on those particles directly or indirectly associated with neutron monitor signals. This revised version was published online in August 2006 with corrections to the Cover Date.     

Solar flare particle measurements with neutron monitors

We discuss the important parameters of solar neutron and proton emissions that can be determined by measurements with neutron monitors at the Earth. First, the methods of analysis for solar neutron events detected by neutron monitors are presented. Illustrations are given to show how these measurements can be used to understand the physics of the neutron production at the Sun. Second, the analytical methods for high-energy interplanetary solar proton events are presented. We then indicate how these observations of interplanetary solar protons can be used to infer the proton acceleration mechanisms at or near the Sun. This revised version was published online in June 2006 with corrections to the Cover Date.