Neutrons and Gamma Rays from Solar Flares

The theory of neutron and gamma-ray production in flares is reviewed and comparisons of the calculations with data are made. The principal conclusions pertain to the accelerated proton and electron numbers and spectra in flares and to the interaction site of these particles in the solar atmosphere. For the June 21, 1980 flare, from which high-energy neutrons and high-energy ( MeV) photons were seen, the electron-to-proton ratio is energy dependent and much smaller than unity at energies greater than 1 MeV. The interaction site of these particles appears to be the solar chromosphere.