Geomagnetic Origin for Transient Particle Events from Nuclear Reactor-Powered Satellites

Abstract

Transient events observed since 1980 by the Gamma-Ray Spectrometer experiment on the Solar Maximum Mission satellite (SMM) have been identified with radiation emitted from 18 different Soviet nuclear reactor-powered satellites. Most of these satellites are similar to Cosmos 954 and 1402 which reentered the atmosphere. Gamma radiation from these satellites was detected when they passed within about 400 to 500 kilometers of SMM. Positron annihilation line radiation (511 kiloelectron volts) and charged-particle events were detected when SMM encountered clouds of positrons and electrons emitted by these satellites and stored up to tens of minutes in the geomagnetic field. The rate of these events varied from about 1 in 5 days to over 30 per day and was strongly dependent on the operating altitudes of the Cosmos satellites and density of the upper atmosphere.

TheSolar Maximum MissionAtlas of Gamma‐Ray Flares

“…As a consequence, particle precipitation events, which typically occurred at locations with low geomagnetic rigidity during geomagnetically disturbed periods, were easily identiÐed by their high shield count rates and relatively weak MCS response. The transients associated with particles and radiation emitted by Soviet nuclear reactorÈpowered satellites (Share et al 1989) occurred primarily (D80%) in 1987 and 1988. Those reactor-generated transients displayed a complex phenomenology with three types of events (Rieger et al 1989), but all types could be straightforwardly identiÐed by their recurrence periodicities and unusual spectral properties.…”

Models for the positive latitude e-e+annihilation feature

“…Artificial injection of positrons into that region of space was discovered in the eighties by SMM when radiation at 511 keV was detected from unshielded satellite-borne reactors (Rieger et al 1989;Share et al 1989). This "nuclear noise" cannot explain the PLE radiation simply because the latter is not a series of regular, short timescale events that could be linked to specific injections.…”