This session shall focus on recent progress in radiation belt research, highlighting the complexity and efficiency of mechanisms leading to impressive acceleration of charged particles in geospace and in other planetary magnetospheres. We solicit modeling and observational contributions on the effects of global magnetospheric processes and local wave-particle interactions on radiation belt dynamics, as well as on aspects of radiation belt coupling with the solar wind, the ring current and the plasmasphere. Of particular interest is the balance between energization and loss due to the combined effect of various electromagnetic waves on radiation belt particles. Presentations utilizing observations from ongoing missions including THEMIS, CLUSTER, Van Allen Probes, Cassini, and Cubesats are strongly encouraged.