Med. Phys. 36 (2009) , Henkner et. al
I
air
from ICRU 49 (85.7 eV), I
water
from Paul et al. (80.8eV)
Inconsistency of recommended I-values water/air:
ICRU 49 (75 / 85.7 eV) vs. ICRU 73 (67.2 / 82.8 eV)
Protons
Carbon
Stopping power ratios: p vs. C-12