Measurement and Intensity of Energetic Electrons at the Equator at 6.6 Re

This paper presents preliminary results of measurements of 50 to 1000 keV electrons at the geomagnetic equator at 6.6 Re. Quiet‐day electron fluxes exhibit a diurnal dip in intensity at local midnight accompanied by a softening of the electron spectrum. During geomagnetically disturbed times the 50 to 150 keV electrons exhibit large fluctuations in intensity; we have denoted these fluctuations as “spikes.” These spikes are largest just after local midnight and decrease in intensity as local time increases. They have a duration of about 1 hr and tend to recur with about a 2‐hr period. The electron spectrum softens considerably during the spikes. Generally the variations in intensity of the electrons correlates excellently with the Kp index.