Initial time dependence of abundances in solar energetic particle events

We compare the initial behavior of Fe/O and He/H abundance ratios and their relationship to the evolution of the proton energy spectra in "small" and "large" gradual solar energetic particle (SEP) events. The results are qual itatively consistent with the behavior predicted by the theory of Ng et al. published in 1999. He/H ratios that initially rise with time are a signatu re of scattering by non-Kolmogorov Alfven wave spectra generated by intense beams of shock-accelerated protons streaming outward in large gradual SEP events.