Figure 4
Comparison of relative biological effectiveness (RBE) factors for different particle types versus kinetic energy for the track structure and LET models and the mean number of cells at risk in annual GCR exposures. (A) Results for protons and 4He. (B) results for 16O, 28Si, and 56Fe. (C) shows a comparison of dose equivalent based on the RBE for Harderian gland tumor prevalence for the track structure and LET dependent targeted effects (TE) models versus aluminum shielding areal density for 0 and 10 cm of tissue depth. (D) Predictions of potential number of cells per year susceptible to targeted effects (TE) and non-targeted effects (NTE) for galactic cosmic ray (GCR) exposures at solar minimum assuming 20 g/cm2 aluminum shielding and 5 cm tissue depth. Also shown are mean number of cells hits per year by δ-rays with an absorbed dose >0.1 mGy. Calculations use the target area for epithelial cells in the Harderian gland of Acell = 24 μm2 with NTE estimates using Abys = 20 Acell as described in the text.
