In February of this year, a team of scientists reported the surprising discovery of a previously unknown third radiation ring — a narrow one that briefly appeared between the inner and outer rings in September 2012 and persisted for a month.
In new research, members of UCLA ESS have successfully modeled and explained the unprecedented behavior of this third ring, showing that the extremely energetic particles that made up this ring, known as ultra-relativistic electrons, are driven by very different physics than typically observed Van Allen radiation belt particles. The region the belts occupy — ranging from about 1,000 to 50,000 kilometers above the Earth's surface — is filled with electrons so energetic they move close to the speed of light.
http://newsroom.ucla.edu/portal/ucla/ucla-scientists-explain-the-formation-248209.aspx