Radiation attenuation technique for simultaneous determination of layer thicknesses in a bi-layered structure

Radiation attenuation has been applied to the measurement of individual layer thicknesses in a bi-layered structure at the Oak Ridge Y-12 Plant. A technique utilizing multiple energies of the transmitted radiation has been developed and requires only one inspection to be made to determine the thickness of each layer. While this technique is applicable to most combinations of materials, the sensitivity to a particular component is dependent upon the amount of radiation attentuation provided by that component. Consequently, this measurement is most accurate when the component of primary interest has a higher Z number than the other constituent