the region to the other and back. Magnetic bottles can be used to temporarily trap charged particles. It is easier to trap electrons than ions, because electrons are so much lighter. 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 belts, which were discovered in 1958 using data obtained by instruments aboard the Explorer 1 satellite. Biconic cusps If one of the poles in the magnetic bottle is reversed, it becomes a biconic cusp, which can also hold charged particles. Biconic cusps were first studied by Harold Grad at the Courant Institute, studies reveal the presence of different types of particles inside a biconic cusp. The most financed cusp approach is the Compact Fusion Reactor which was supported by Lockheed-Martin starting in 2007. See also List of plasma (physics) articles Polywell Magnetic mirror point Notes References Citations Bibliography External links Lecture Notes from Richard Fitzpatrick Soviet inventions