Modeling the 2017 September 10 Long Duration Gamma Ray Flare*

The large flares of 2017 September 4 to 10 were significant microwave events with revealing multi-wavelength images of the flare environment. The event on September 10 was a large long-duration, gamma-ray flare (LDGRF). The event also produced a Ground Level Enhancement (GLE). Using the microwave imaging data from the Expanded Owens Valley Solar Array (EVOSA) we interpret and model the behavior of the energetic-flare protons of September 10 as measured with the Large Area Telescope (LAT) on the Fermi mission.  We do this in the context of stochastic acceleration in a large coronal bipolar structure to produce the high-energy long-duration gamma-ray emission.  Our preliminary analysis suggests that the acceleration of the GeV protons takes place in a large structure about 1.4 solar radii in length.  The requirements for the magnetic field and turbulence in this structure will be presented.