Lead
Published: Oct 12, 2018
With respect to Radiation Protection, lead together with perhaps concrete, is the most likely shielding material for attenuating X-Rays and Gamma Rays. It has a density approximately 11 times greater than that of water and is easily formed into sheets and interlocking bricks. For example, 4 cm lead will attenuate Co-60 gamma rays to 1/10th of the unshielded value (ignoring geometric and beam effects).