Detection of solar particle events inside FPGAs

Abstract

The intensity of radiation in space, which is affected by the sun, can differ over five orders of magnitude within a few days. This variation is caused by shocks of fast coronal mass ejections, which drive high-energy and long-duration particle events, named solar particle events. With the knowledge of the current solar condition, operators can take countermeasures. They can save unnecessary redundancy during relaxed periods or switch the system in a safe state during a harsh period. We propose the block RAM inside the FPGA as a single-event upset sensor to detect solar particle events. The user can still access these block RAMs because we only evaluate the error signals from the error-correcting code logic. We are developing a solar condition detector including a model for statistical classification. This is based on Petri nets and we perform static as well as transient analyses to check the plausibility and to determine the detection time. By combining the evaluation of the model with the results of the implemented FPGA design, we detect the significant June 2015 solar particle event after 13.1 min (784 s), using all 298 block RAMs of a Virtex-5QV. The duration of this solar particle event was 56 h and the peak particle flux occurred after 21.6 h as energetic storm particle. We conclude, that solar particle events cause a highly dynamic radiation environment, but the onset of such high-intensity events can be detected and a response can be organized in a timely manner.