Generation of gamma radiation and neutrons in solar flares.

Thin-target and thick-target models are used to interpret data on the rates of generation and the total amount of neutrons and gamma rays produced in the flare of 4 August 1972, with special attention given to flare-related acceleration of particles and the dynamic characteristics of microwave, X-ray and gamma-ray emission. It was determined that the total amount of accelerated particles was (8 plus or minus 2) x 10 to the 33rd and (1.2 plus or minus 0.4) x 10 to the 33rd for the thin-target and thick-target models, respectively. The maximum intensity of neutrons at the earth occurred 2000-4000 sec after the start of nuclear reactions and was of the order of 0.008 per sq cm per sec per MeV for energies of 10-30 MeV. The relative concentration of He-3 in the neutron capture region (subphotospheric layers with a depth of 1.5-5 g/sq cm) was found to exceed three times that in the solar wind.