The effect of water can be seen as the result of its high
hydrogen content. It is also noticed that as the concentration of boric
acid solution increases, the attenuation increases. For the foam
samples filled with 2% and 3% (w/v) boric acid in water, the 1.5 in.
thickness samples totally stopped the beam, which is due to the high neutron absorption cross-section of boron-10 in the boric acid
solution.