X-rays Shielding Calculation

Like gamma rays, X-rays have no definite range - the intensity of radiation transmitted through a material falls exponentially with the thickness of the material. Tungsten alloy X-rays shielding become more and more popular for radiation protection. Following is the calculation:

I = Io e-ux

where u is the linear attenuation coefficient of the material

For typical 50 KeV X-rays the half value thicknesses, H1/2 = 0.69/u, for some common materials are

         Air                     H1/2 ~ 10m

        Body tissue          H1/2 ~ 3 cm

        Lead (Pb)             H1/2 ~ 0.1 mm

        Steel                    H1/2   ~ 0.5 mm

An attenuation of I/Io = 10-10 is achieved by lead of thickness 3.3 mm or by steel of thickness 16.6 mm.