Ne/O and Fe/O Characteristics of Large Solar Energetic Particle Events during Solar Cycles 23 and 24

We have examined the Ne/O and Fe/O characteristics of large solar energetic particle (SEP) events at ion energy range 3–40 MeV nucleon?1 during cycles 23 24. In each cycle, activity displays an ?3 yr rising phase a longer declining phase. While Fe-poor only appeared in cycle 23, properties Fe-rich were similar phases both cycles. Also, very few seen addition, data corona, wind, SEP consistently reveal that are mainly governed by wind turbulence status exhibits significant difference between slow fast streams. During cycles, streams dominated two-dimensional component, which significantly reduces injection quasi-perpendicular (Q-Perp) shock acceleration. increased ratio hence enhanced temperature coronal suprathermals, favoring occurrence events. contrast, slab could increase Q-Perp Consequently, streams, most originate from jet suprathermals. The suprathermals may produce having abnormally low ratios provided speed associated mass ejection is enough.