Possible ground‐level measurements of solar neutron decay protons during the 19 October 1989 solar cosmic ray event

Abstract

The high energy solar proton event of 19 October 1989 had an atypical particle anisotropy during the initial phase with the Deep River, Ottawa and Goose Bay neutron monitors in the Eastern Canadian region recording the intensity increase about 25 minutes before comparable detectors in Europe and Western Canada. Using the asymptotic cones of acceptance for these neutron monitors, we show that this early onset in the particle intensity increase may be the detection of relativistic protons that are the decay product of solar flare generated relativistic neutrons.