Do protons or electrons dominate particle acceleration in solar flares?

Abstract

Particles are accelerated in solar flares, and observations indicate that energetic flare particles are present in both the interplanetary medium and the outer solar atmosphere (chromosphere and corona). The controversy addressed in these articles is whether the most important accelerated species in the solar atmosphere are electrons or protons. We will not be concerned with interplanetary particles. Resolution of this controversy should shed light on particle acceleration processes elsewhere in the universe. For many years it was widely believed that electrons constituted the dominant accelerated species. However, in the mid‐1980s, George Simnett expressed the seemingly heretical view that protons may dominate. While Simnett's suggestion has been either ignored, or strongly criticized, a recent observation of Ramaty et al. [1995] may indicate that significant energy resides in accelerated protons.