Robust determination of mass attenuation coefficients of materials with unknown thickness and density

•Mass attenuation coefficients of materials with unknown thickness and density.•Simultaneous emission of photons of different energy.•Accurate determination of mass attenuation coefficient.

An alternative approach is used to measure normalized mass attenuation coefficients (µ/ρ) of materials with unknown thickness and density. The adopted procedure is based on the use of simultaneous emission of Kα and Kβ X-ray lines as well as gamma peaks from radioactive sources in transmission geometry. 109Cd and 60Co radioactive sources were used for the purpose of the investigation. It has been observed that using the simultaneous X- and/or gamma rays of different energy allows accurate determination of relative mass attenuation coefficients by eliminating the dependence of µ/ρ on thickness and density of the material.