Column of Water Length

Column of Water Needed to Cut Photon Count in Half at 10 MeV

[math] e^{-n \sigma t} [/math]

[math]n = \frac{atoms}{cm ^{3}} =\gt \frac{\frac{g}{cm^{2}}{\frac{g}{mol}}} \times 6.022 \cdot 10^{23} \frac{atoms}{mol} =\gt \frac{atoms}{cm^{3}}[/math]