Low Energy Solar Cosmic Ray Latitude Intensity Structure and Pitch Angle Distributions at Low Altitude

摘要

Solar protons (1.1 - 1.6 MeV) and alpha particles (4.1 - 15 MeV) were observed over the polar caps associated with the proton event of 28 August 1966. Persistent latitudinal structure in the proton flux was observed. Ordering of the structure by magnetic latitude over both polar caps during a given orbit shows that it is a spatial effect associated with non-uniform access of solar protons to high latitudes. Examples of the latitudinal structure are shown. Pitch angle distributions were observed, which clearly delineated a region of quasi-trapping; the changes in the pitch angle distributions during a representative pass as the spacecraft, 1966-70A, traversed the region of quasi-trapping are shown. No evidence for the durable containment of the quasi-trapped solar alpha particles was observed. (Author)