Understanding variations of galactic energetic particles in the heliosphere: modelling and radiation hazard assessment

Abstract: The intensity and energy spectrum of energetic charged radiation in the heliosphere are significantly influenced by solar activity. This phenomenon is known as solar modulation of galactic cosmic rays. As interplanetary travel becomes a reality, missions in low Earth orbit become longer and more frequent. In low Earth orbit we need to estimate the influence of Earth's magnetosphere accurately to assess the radiation hazard experienced by astronauts during space missions, there is an emergent need for accurately depicting the space radiation environment and predicting the cosmic-ray flux in the heliosphere. Here we present a new effective and predictive model of solar modulation which incorporates fundamental physics processes of particle transport such as diffusion, convection, and adiabatic cooling to compute the energy spectrum; and temporal evolution of cosmic radiation in the inner heliosphere. Empowered by this model and a time-dependent effective description of the geomagnetic field, we will show our estimates of the dose rates experienced by astronauts over time, as they orbit Earth onboard the International Space Station and while travelling through interplanetary space.