A double-peaked inner radiation belt: cause and effect as seen on CRRES

Data from the Combined Release and Radiation Effects Satellite (CRRES) show the formation of a second peak in the inner proton radiation belt during the Sudden Storm Commencement (SSC) at 03:42 UT on 24 March 1991. The authors believe that the injection of high energy protons into an L-shell of 2.55 R_F is directly related to the solar-initiated shock accompanying the SSC. Once injected, the greater than 20 MeV protons became stably trapped and produced the second peak in the proton belt that continues for months after the event. The secondary peak protons increased single event upset rates in microelectronic test devices on CRRES by over an order of magnitude in the region of the second peak, that is, for L-values of 1.8 R_F to 2.6 R_E. This second belt has far-reaching effects for radiation belt modelers and for determining radiation degradation and single event upset (SEU) levels that must operate in this region of near-Earth space