The geomagnetically trapped corpuscular radiation

Abstract

Introduction—One of the most interesting geophysical discoveries of recent years was that made with the early United States satellites Explorer I (satellite 1958α) and Explorer III (satellite 1958γ). It was found [Van Allen, 1958; Van Allen and others, 1958] that an immense region around the earth is occupied by a very high intensity of charged particles (protons and electrons), temporarily trapped in the geomagnetic field. The detailed study of this radiation has been a major endeavor of the past year and a half by a group at the State University of Iowa in the United States, and by IGY workers in the Soviet Union. Important additional information at relatively low altitudes has been obtained in rocket experiments flown by other workers.

Space Weather: Historical and Contemporary Perspectives

“…Neither did John Pierce at AT&T Bell Laboratories when he proposed the low altitude active communications satellite Telstar-1 (launched in July 1962). The surprising discovery by Van Allen (1959) with an instrument on the Explorer 1 satellite of the intense fluxes of radiation trapped in Earth's magnetic field meant that any technologies that humans placed into space would have to contend with this radiation. Research on Earth's (and the interplanetary medium) radiation environment continues at a high and sophisticated level to this day.…”

Online NARMAX model for electron fluxes at GEO

“…Although the radiation belts were discovered more than half a century ago (Van Allen, 1959), during the very first in situ space measurements, there still lacks a comprehensive physical model of the solar wind interaction with the terrestrial magnetosphere and the dynamics of the radiation belts. Reeves (1998) investigated the relationship between the disturbances within the magnetosphere and radiation belts, which was found to be very complex.…”

Ionizing Radiation and Life

“…Figure 1 presents a diagram that summarizes the different CR sources relevant to this discussion: SEP, GCR, trapped particle belts, and induced emissions from CR interactions. A significant radiation source for potentially habitable moons orbiting within the magnetic field of their planet, such as Europa or Titan, are charged particles trapped in circular regions within the dipolar field, which in the terrestrial situation are known as the Van Allen belts (discovered by the Explorer I satellite, Van Allen, 1959, and reviewed recently by Benton and Benton, 2001). Induced emissions are comprised of albedo particles generated by nuclear reactions in CR secondary cascades (explained in more detail below) that backscatter upwards.…”