The attenuation coefficient is a quantity that characterizes how easily a material or medium can be penetrated by a beam of light, sound, particles, or other energy or matter. A large attenuation coefficient means that the beam is quickly "attenuated" (weakened) as it passes through the medium, and a small attenuation coefficient means that the medium is relatively transparent to the beam. The Attenuation Coefficient is also called linear attenuation coefficient, narrow beam attenuation coefficient, or absorption coefficient.
$F(x) = Ae^{-\alpha x} \cos{[\beta (x - x_0)]}$, then $\alpha$ is the attenuation coefficient and $\beta$ is the phase coefficient.
Applicable units are those of quantitykind:AttenuationCoefficient
Attenuation Coefficient