Space and terrestrial cosmic-ray environments estimated using PHITS and EXPACS

Sato, Tatsuhiko   ; Abe, Shinichiro   ; Nagamatsu, Aiko*

Evaluation of cosmic-ray environment is essential in the estimate of soft error rates (SER) of semiconductor devices used not only in spacecraft but also on the Earth. This paper briefly summarizes the features of our developed models for calculating space and terrestrial cosmic-ray fluxes, which are based on the Particle and Heavy Ion Transport code System (PHITS) and EXcel based Program for calculating Atmospheric Cosmic-ray Spectrum (EXPACS), respectively. Examples of the calculated SERs obtained using EXPACS are also presented, in comparison with the corresponding data obtained using the standard model described in JESD89A. The difference between the calculated SERS is probably attributable to the inaccuracy associated with the simple scaling method adopted in the JESD89A model.