Solar Energetic Particle Event Doses in LEO: Sensitivities to Event Spectra, Orbital Parameters, and Geomagnetic Field Conditions

This paper presents a study of the sensitivities of calculated doses to the skin, ocular lens of the eye and bone marrow, for crewmembers in low Earth orbit, to variations in solar energetic particle event fluence levels and spectral hardness, spacecraft orbital inclination, geomagnetic field storm levels (Kp index), and spacecraft shielding thickness. In general, doses increase for higher inclination orbits, for higher Kp indices, and for harder SPE spectra. The predicted doses sometimes change dramatically for even small variations in the assumed conditions. For large events in high inclination orbits, with a highly disturbed geomagnetic field, doses can be very hazardous to crews.