Core plus halo model for GLEs

We model a scenario in which particles are accelerated near the Sun in a shock wave with a fraction transported back to the solar surface to radiate, while the remainder is detected at Earth in the form of a GLE. The high-energy particle emissions are studied for a spherical shock wave propagating in radial magnetic field through a highly-turbulent radial ray (the acceleration core) and surrounding weakly-turbulent sector in which the accelerated particles can propagate towards or away from the Sun. The model accounts for both the first-order Fermi acceleration at shock front and the second order, stochastic re-acceleration by the turbulence enhanced behind the shock.