# Linear attenuation coefficient

## Definition

The linear attenuation coefficient $\mu(E)$, or preferably $\mu_{TOT}(E)$ 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.

$\mu_{TOT}(E)$ is given by

$\mu_{tot} = \Big[{\mu\over\rho}\Big]_{TOT}\rho$

where $\rho$ is the density of the material in g/cm3.

## 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].