Absolute intensities of geomagnetically trapped particles with Explorer 14

This is the initial report on a new series of observations on the absolute intensities of geomagnetically trapped protons and electrons in the earth's outer radiation zone and on the nature of the outer boundary of the magnetosphere. The equipment was carried on the NASA satellite Explorer 14, which was launched on October 2, 1962, into an eccentric orbit whose apogee was initially at 16.5 earth radii from the center of the earth on a line at 71° to the line from the center of the earth to the sun. Sample omnidirectional intensities of electrons on October 5, 1962, near the magnetic equatorial plane were at a geocentric radial distance of 39,000 km; and of electrons and protons at a geocentric radial distance of 20,000 km. There are large fluctuations from day to day.