Abstract
The shape of the energy spectra of cosmic rays contains information about the acceleration proeess. We propose to probe solar cosmic ray sources by the analysis of the source energy spectrum. By comparing theoretical source spectra with experimental spectra of high energy solar protons, we attempt to improve to the understanding of the generation process of flare particles. The analysis is constrained to multi-GeV proton events, since postacceleration modulation is less pronounce on high energy particles. It is deduced that the processes undergone by particles at the sources are directly related to the parameter of acceleration efficiency, a. We find that the generation process of solar particles occurs under three main regimes: events of high efficiency events where energy losses are completely negligible during acceleration; low efficiency events where the acceleration spectrum is strongly modulated by energy losses during the short time scale of the phenomenon; and events with an intermediate regime of a, high enough to overtake adiabatic changes, but not so coulombian losses and energy degradation from pp interactions. An interesting correlation with the plasma temperature at the sources is discussed. The deduced values of the acceleration efficiency a = (0.1-1.5) 1 allow us to estimate the range of variation, from event to event, of some of the physical parameters prevailing at the sources, and those characterizing the acceleration process itself.
