Which of the following formulas correctly relates the half-thickness of a material, , to its linear attenuation coefficient, ?
A beam of X-rays is directed toward a thick gold sheet. Each X-ray photon in the beam has an energy of 2.21 keV, and the half-thickness of gold for 2.21 keV photons is 0.391 cm. What is the intensity of the beam, as a ratio of the initial intensity, once it has passed through 0.8 cm of the gold sheet? Give your answer to 3 significant figures.
Lead has a density of 11.3 g/cm3. The linear attenuation coefficient for lead is 0.148 cm−1 for 10 keV X-rays. What is the mass attenuation coefficient for lead for 10 keV X-rays? Give your answer to 3 significant figures.