Observations of SEE phenomena using CCDs, "seeing SEEs"

Cosmic-radiation-induced single event effects (SEEs) in avionics are largely due to secondary neutrons generated when primary cosmic ray particles interact with atmospheric molecules. They occur when high-energy neutrons cause bursts of spurious charge through interactions with atomic nuclei in electronic devices. This behaviour can result in a range of upset mechanisms including memory state inversion, avalanche breakdown, and latch up. This presentation describes the results of recent work using imaging charge-coupled devices (CCDs) to study the transient charge generated in a silicon lattice during neutron-induced SEEs. This technique permits SEEs to be directly observed with high spatial resolution, allowing the shape of generated charge clouds to be determined. Results were presented from experiments performed during accelerated testing in simulated atmospheric neutron spectra. Analysis of the SEE image data was described. Information of considerable scientific and technological interest can be extracted from these data; examples given in this presentation includes classification of event species and derivation of single event upset (SEU) multiplicity statistics, both of which require the spatial information which CCDs provide. Development of an imaging cosmic radiation monitor, to observe SEE phenomena in the natural environment, was described