Authors: J.M. Ryan (UNH), Bruno, A. (CuA), de Nolfo (GSFC), A. Hutchinson (CuA), S. Dalla (UCLAN)

Superficial similarities exist between Long Duration Gamma-Ray Flares (LDGRF), emitting 100 MeV gammas, and Ground Level Enhancements.  A sometimes common agent is an interplanetary shock produced by a CME, suggesting a common source for both phenomena.  However, detailed comparisons quickly fail.  Key failures include unsatisfactory correlations of SEPs with gamma emissions as well as unsatisfactory correlations of gammas and particle acceleration surrogates, e.g., Type II onsets.  Also, among these failures are CMEs with no gammas and gammas with no CME and the absence of a workable particle acceleration/transport model for (1) an efficient, but not too efficient, number of energetic particles that (2) allows the particles to be contained long enough for acceleration while awaiting release and transport to the Sun over enormous heliospheric distances.   Lastly, a key feature of the LDGRF is a significant delay between the flare impulsive phase and the high-energy extended emission and trying to fit that into an interplanetary shock model.  That delay, at least for two landmark events, does not exist, as evidenced by solar neutron observations showing no such delay.  These problems vanish if one decouples the CME from the LDGRF and focuses on a low altitude acceleration and trapping scenario.