I.3 Cosmic ray environment and effects models
Cosmic ray environment and effects models were originally created by Adams and coworkers at the U.S. Naval Research Laboratory [RD.77], under the name CREME. They provided a comprehensive set of cosmic ray and flare ion LET and energy spectra, including treatment of geomagnetic shielding and material shielding. CREME has been superseded by CREME96 [RD.78]. The major differences to the environment specification are in the inclusion of a model of the cosmic ray environment and its solarcycle modulation due to Nymmik et al. [RD.79], improved geomagnetic shielding calculation, and more realistic Solar Energetic Particle event (SEP) ion environments (see clause 9.2.3).
The cosmic ray fluxes are anticorrelated with solar activity so the highest cosmic ray fluxes occur at solar minimum.