Editing Magnetic mirror (section)

== Magnetic bottles ==
[[File:Fields in magnetic bottles.jpg|thumbnail|This image shows how a charged particle will corkscrew along the magnetic fields inside a magnetic bottle, which is two magnetic mirrors placed close together. The particle can be reflected from the dense field region and will be trapped.]]

A '''magnetic bottle''' is two magnetic mirrors placed close together. For example, two parallel coils separated by a small distance, carrying the same current in the same direction will produce a magnetic bottle between them. Unlike the full mirror machine which typically had many large rings of current surrounding the middle of the magnetic field, the bottle typically has just two rings of current. Particles near either end of the bottle experience a magnetic force towards the center of the region; particles with appropriate speeds spiral repeatedly from one end of the region to the other and back. Magnetic bottles can be used to temporarily trap charged particles. It is easier to trap [[electron]]s than ions, because electrons are so much lighter.<ref>"A biased probe analysis of potential well formation in an electron only, low beta Polywell magnetic field" Physics of Plasma, May 9, 2013, Vol 20, 052504</ref> This technique is used to confine the high energy of plasma in fusion experiments.

In a similar way, the Earth's non-uniform magnetic field traps charged particles coming from the Sun in doughnut shaped regions around the Earth called the ''[[Van Allen radiation belt]]s'', which were discovered in 1958 using data obtained by instruments aboard the [[Explorer 1]] satellite.