Initial conditions for radiation analysis: models of galactic cosmic rays and solar particle events

During interplanetary missions the radiation conditions are determined by fluxes of Galactic Cosmic Ray (GCR) particles and Solar Energetic Particles (SEP). The particle fluxes of these two high-energy radiation components differ fundamentally in energy spectra and have the opposite dependence on solar activity level. One of the key issues, associated with estimating flight conditions for missions to the Moon, various asteroids and Mars, is the relative balance between GCR and SCR, depending on the level of solar activity and the distance to the Sun for both open space conditions and conditions inside the spacecraft. This task can be solved with sufficient accuracy only when using such particle flux models (of the above mentioned radiation sources), which are based on unified parameters, describing the current solar activity level. Such models, employing smoothed Wolf numbers as the initial parameter, were developed at SINP MSU. These models are - the semi-empirical model of GCR fluxes, which has currently been approved as an international standard (ISO 15390), and the probabilistic model of SEP particle fluxes, which is currently under discussion as a draft international standard (ISO DRAFT 15391). The report presents a survey of experimental data on GCR and SEP fluxes in interplanetary space at various solar activity levels, and an analysis of the reliability and completeness of data on these fluxes, provided by various calculation models.