4.4 The acceleration of SEPs
The sudden release of huge amounts of energy in flares and CMEs is an issue with many unsolved
problems. One of them concerns the acceleration of electrons and ions to such extremely high
energies. From the manifold observations discussed above we have already many hints about the
mechanisms involved. On the other hand, these observations will help to decide on whether a
theoretical model is correct or not. In this review, I will not elaborate on this multi-faceted
subject and rather leave it to other reviews to come. In the meantime, the interested reader
may wish to study the articles in the book by Klein (2003), in particular the one by Kliem
et al. (2003).
