Research on spectrum effect on attenuation coefficient with analytical method

The relation between the line attenuation coefficient and the material thickness of FTO has been studied, and the function between them has been given. The results show that the efficient linear attenuation coefficient decreases when the thickness of material increases in the transmission direction of Xray. Specially，the average efficient attenuation coefficient in the FTO is 0.838cm－1 for tungsten with precision of 4.5% and 0.297cm－1 for copper with precision of 5.0%. The spectrum effect on attenuation coefficient is less than 5%. The material densities can be reconstructed with such precision.