where (l/q) is mass attenuation coefficient (cm2/g), q and v are the
density (cm3/g) and the thickness of the sample (cm). The higher
the (l/q) value, the less energy passes through the material. In this
paper, we also introduce the half value thickness (HVT) to characterize
radiation shielding property directly. The HVT equals the
thickness of a sample when the intensity of the transmission beam
I was attenuated to half of the intensity of the incoming beam I0. The comparison of photon attenuation characteristics of shielding
materials at various energies of ray photons are given in Fig. 6.