Fig. 7
a Ratios of total mass stopping powers for different tissues to those for water, including values with I-values changed for adipose tissue, bone and water, and for ρwater=2 g cm3 (see text), as a function of the electron kinetic energy. b Monte Carlo-calculated total electron fluence differential in energy (per incident fluence) in a ∼20 cm3 water volume at a depth of 10 cm for 6 MV photons (left ordinate axis); the right axis corresponds to the cumulative dose fraction (CDF), showing that electrons below ∼ 0.75 MeV contribute to 50% of the absorbed dose. Adapted from ref. [55]