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The attenuation coefficient of a volume, denoted μ, is defined as [6] =, where Φ e is the radiant flux;; z is the path length of the beam.; Note that for an attenuation coefficient which does not vary with z, this equation is solved along a line from =0 to as:
In chemistry, the molar absorption coefficient or molar attenuation coefficient (ε) [1] is a measurement of how strongly a chemical species absorbs, and thereby attenuates, light at a given wavelength. It is an intrinsic property of the species.
In chemistry, mass attenuation coefficients are often used for a chemical species dissolved in a solution.In that case, the mass attenuation coefficient is defined by the same equation, except that the "density" is the density of only that one chemical species, and the "attenuation" is the attenuation due to only that one chemical species.
In engineering, attenuation is usually measured in units of decibels per unit length of medium (dB/cm, dB/km, etc.) and is represented by the attenuation coefficient of the medium in question. [1] Attenuation also occurs in earthquakes; when the seismic waves move farther away from the hypocenter, they grow smaller as they are attenuated by the ...
absorption coefficient is essentially (but not quite always) synonymous with attenuation coefficient; see attenuation coefficient for details; molar absorption coefficient or molar extinction coefficient , also called molar absorptivity , is the attenuation coefficient divided by molarity (and usually multiplied by ln(10), i.e., decadic); see ...
To describe the attenuation coefficient in a way independent of the number densities n i of the N attenuating species of the material sample, one introduces the attenuation cross section = (). σ i has the dimension of an area; it expresses the likelihood of interaction between the particles of the beam and the particles of the species i in the ...
The mass attenuation coefficient can be looked up or calculated for any material and energy combination using the National Institute of Standards and Technology (NIST) databases. [ 7 ] [ 8 ] In X-ray radiography the calculation of the mean free path is more complicated, because photons are not mono-energetic, but have some distribution of ...
In physics, the attenuation length or absorption length is the distance λ into a material when the probability has dropped to 1/e that a particle has not been absorbed. Alternatively, if there is a beam of particles incident on the material, the attenuation length is the distance where the intensity of the beam has dropped to 1/ e , or about ...