(ln 2) of the penetration depth. Engineers use these equations predict how much shielding thickness is required to attenuate radiation to acceptable or regulatory limits. Attenuation coefficient is also inversely related to mean free path. Moreover, it is very closely related to the attenuation cross section. Other radiometric coefficients See also Absorption (electromagnetic radiation) Absorption cross section Absorption spectrum Acoustic attenuation Attenuation Attenuation length Beer–Lambert law Cargo scanning Compton edge Compton scattering Computation of radiowave attenuation in the atmosphere Cross section (physics) Grey atmosphere High-energy X-rays Mass attenuation coefficient Mean free path Propagation constant Radiation length Scattering theory Transmittance References External links Absorption Coefficients α of Building Materials and Finishes Sound Absorption Coefficients for Some Common Materials Tables of X-Ray Mass Attenuation Coefficients and Mass Energy-Absorption Coefficients from 1 keV to 20 MeV for Elements Z = 1 to 92 and 48 Additional Substances of Dosimetric Interest Physical quantities Radiometry Acoustics