Relative timing of solar prompt gamma-ray line and X-ray emission expected from a trap plus precipitation model for protons and electrons

"Trap-plus-precipitation" models of how flare-produced energetic particles produced (nominally) somewhere in the corona, where they can be trapped by the mirror force, eventually can interact in the deep atmosphere. There, if they are ions above a few MeV, they may undergo nuclear collisions and thereby emit γ-rays. See the Najita-Orrall cartoon for the introduction of this concept. The "trap region", though shown in a rectilinear form here, would likely consist of a system of closed magnetic fields, which would guide the precipitation of the particles.