Research Directed Toward Evaluation of Radiation Environment of Near-Earth Space

摘要

As a result of the correlation study of the sudden intensity increases seen by the ATS-1 electron spectrometer with the occurrence of magnetic substorms the following conclusions are reached: (1) Electrons are produced in the 50-150 kev energy range as observed at 6.6Re during a magnetic substorm. (2) The electrons are produced at or near the midnight meridian and then drift on closed field lines around the earth. (3) The electron bunch produced as a result of the substorm in 75% of the 60 events studied is associated with precipitation observed by riometers as it drifts. (4) The frequency of occurrence of such particle substorms indicates that they might represent a quasi-steady source of electrons for the trapped radiation. Rapid fluctuations in the intensity of precipitated energetic particles during a bright aurora have been studied. The fluctuations occurred only during the period of peak precipitation and in close correlation with the peak precipitation and in close correlation with the westward surge of a bright auroral band preceding break-up. Dynamic spectral analysis of the data showed no sustained periodicities. (Author)