Numbers of Protons Accelerated in Solar Flares

Abstract

Numbers of solar protons accelerated at flare sites are derived from gamma-ray observations of the C deexcitation line at 4.44 MeV and the neutron capture line at 2.22 MeV from the 1981 Apr. 1, 1981 May 13, 1981 Oct. 15 and 1982 June 6 flares. The derived numbers of protons accelerated to energies above 10 MeV are of the order of 10³². The number of protons producing gamma-ray lines seems to be much higher than the number of escaping protons from the Sun. The present result suggest that most of protons stream down and produce gamma-ray lines, and only a small fraction of protons escapes into interplanetary space.