# Linear attenuation coefficient

### From Online Dictionary of Crystallography

Absorptionskoeffizient, linearer Schwächungskoeffizient (*Ge*). Coeficiente de atenuación lineal (*Sp*).

## Definition

The linear attenuation coefficient μ(*E*), or preferably μ_{TOT}(*E*) in cm^{−1}, is a measure of the photon beam attenuation by a material due to absorption and scattering processes and hence differs from the absorption coefficient, which is a measure of beam attenuation due to absorption processes only.

μ_{TOT}(*E*) is given by

where ρ is the density of the material in g cm^{−3}.

## History

Coefficients for converting between these units are given by many authors [Cohen, E. R. and Taylor, B. N. (1987). *Rev. Mod. Phys.* **59**, 1121-1148; Creagh, D. C. and McAuley, W. J. (1992). *International Tables for Crystallography, Volume C*, ed. A. J. C. Wilson, Dordrecht: Kluwer; Chantler, C. T. (1995). *J. Phys. Chem. Ref. Data* **24**, 71-643].