Observation of Nearly Monoenergetic High-Energy Electrons in the Inner Radiation Belt

Some sharply peaked electron spectra observed in the inner belt are presented. The data were acquired during the period 30 October to 4 November 1963, shortly after a major magnetic storm, in the narrow spatial interval where McIlwain's L parameter varies from 1.14 to 1.17, corresponding to a region where the high-energy electrons from Starfish had long since decayed. The electrons observed at 1.3 MeV decayed at a rate in reasonable agreement with that calculated from atmospheric scattering theory, both with respect to absolute value and variation with L.