Pion-induced soft upsets in 16 mbit DRAM chips

Measurements of the soft upset cross section due to energetic charged pions were made in various 16 Mbit memory chips, as a function of incident pion energy and for chips with different cell technologies. Significant differences are seen to exist between cell technologies, up to a factor of 1000 in cross section. Upset cross sections are reported that exhibit proportionality to the reaction cross section for pions on silicon, including the well-known enhancement over proton and neutron cross sections near the delta resonance. Implications of this enhancement for pion-induced upsets due to cosmic ray fluxes are discussed.