The Van Allen radiation belt is a torus of energetic charged particles (plasma) around Earth, held in place by Earth’s magnetic field. Earth’s geomagnetic field is not uniformly distributed around its surface. On the sun side, it is compressed because of the solar wind and on the other side, it is elongated to around three earth radii. This creates a cavity called the Chapman Ferraro Cavity, in which the Van Allen radiation belts reside. The Va Chapman n Allen belts are closely related to the polar aurora where particles strike the upper atmosphere and fluoresce.
Energetic electrons form two distinct radiation belts, while protons essentially form a single belt.
In addition to protons and electrons, the belts contain lesser amounts of other nuclei, such as alpha particles.
The term Van Allen belts refers specifically to the radiation belts surrounding Earth; however, similar radiation belts have been discovered around other planets. The Sun does not support long-term radiation belts. The Earth’s atmosphere limits the belts’ particles to regions above 200–1,000 km, while the belts do not extend past 7 Earth radii RE.The belts are confined to an area which extends about 65° from the celestial equator.
An upcoming NASA mission, Radiation Belt Storm Probes will go further and gain scientific understanding (to the point of predictability) of how populations of relativistic electrons and ions in space form or change in response to changes in solar activity and the solar wind.
Several NASA Institute for Advanced Concepts–funded studies are exploring whether it might be possible to use magnetic scoops to collect theantimatter that occurs naturally in the Van Allen belts of Earth, and ultimately, the belts of gas giants like Jupiter, hopefully at a lower cost per gram than laboratory production of antimatter.
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