Effect of CME Interactions on the Production of Solar Energetic Particles

We analyzed a set of 52 fast and wide, frontside western hemispheric (FWFW) CMEs in conjunction with solar energetic particle (SEP) and radio burst data and found that 42 of these CMEs were associated with SEPs. All but two of the 42 SEP-associated FWFW CMEs (95%) were interacting with preceding CMEs or dense streamers. Most of the remaining 10 SEP-poor FWFW CMEs had either insignificant or no interaction with preceding CMEs or streamers, and were ejected into a tenuous corona. There is also a close association between type II radio bursts in the near-Sun interplanetary medium and SEP-associated FWFW CMEs suggesting that electron accelerators are also good proton accelerators.