Cosmic-Ray Neutron Increase from a Flare on the Far Side of the Sun

Abstract

An injection of solar cosmic radiation, which occurred on November 2O, 196O, seemed to have originated in a large unseen flare which occurred at a solar longitude some l2O deg W of the center of the solar disk or about 3O deg behind the west limb of the sun. At 2lOO hr U.T. on November 2O, a sudden increase in neutrons was observed at Sulphur Mountain, Deep River, and Churchill, Canada. The characteristic shape of the increase, the fact that it was relatively much larger at a mountain station, and its absence in a meson telescope at the same station indicated that it was produced by solar protons. (M.C.G.)