Energy dependence in solar cosmic ray composition

A study of energy dependence in elemental abundances of eight large solar-flare associated particle events reveals a wide range of variation in the Fe(group)/O ratios from event to event. While the energy dependence is consistent in most events with individual element spectra approximately exponentials in rigidity, several events show unusual behavior in the Fe(group)/O ratio due to the existence of several distinct spectral components. These multiple spectral components may imply multiple phases of acceleration or substantial interplanetary shock contamination at low energies at times well before the arrival time of these shocks at 1 AU