Fig. 2
From: Limitations in predicting the space radiation health risk for exploration astronauts
Relative abundance of atomic species, normalized to Z = 1 (hydrogen) and up to Z = 26 (iron), in the Galactic Cosmic Ray (GCR) spectrum. The GCR spectrum includes every atom in the periodic table, with ions up to nickel (Z = 28) contributing to any significance. Note the energy of each ion species varies widely, more prominently in the range of 400–600 MeV. This broad disparity in ions and energies makes it extremely difficult to accurately simulate the GCR environment during ground-based radiobiology experiments. While larger ions may provide lower relative contribution to the spectrum makeup they may have a more significant biological impact than smaller, abundant ions. Data adapted from Saganti et al. 2014108
