Attenuation Coefficient


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attenuation coefficient

[ə‚ten·yə′wā·shən ‚kō·ə′fish·ənt]
(electromagnetism)
The space rate of attenuation of any transmitted electromagnetic radiation.

Attenuation Coefficient

 

(or extinction coefficient), a quantity inverse to the distance at which the radiation flux forming a parallel beam is attenuated as a result of the joint action of the absorption and scattering of light in a medium by a specified factor. When the factor is 10, the coefficient is called the decimal attenuation coefficient, and when the factor is e, it is called the natural attenuation coefficient. The attenuation coefficient is the sum of the absorption coefficient and the scattering coefficient of the medium. These coefficients depend on the set of frequencies v, or wavelengths λ, that characterize the initial flux. The value of the attenuation coefficient for the limiting case of a single frequency v is called the monochromatic attenuation coefficient. Like the absorption and scattering coefficients, the attenuation coefficient can be divided by the volume of the medium or by the mass of the attenuating substance; we shall call these two ratios the volume and mass attenuation coefficients, respectively.

References in periodicals archive ?
For a rubber compound, the sound attenuation coefficient a is the sum (equation 3) of the products of the sound attenuation coefficients an and the concentration [n] of the respective compound ingredients n expressed by the volume fractions [n] = [V.
The study reached the following major conclusions: (1) This paper defined a temperature attenuation coefficient, a, which is an important parameter for the solutions of the coupled problem, because the temperature profile of smoke is shown to be exponential functions of a.
where S(E) is the photon spectrum (unnormalized fluence spectrum), [mu](E) is the photon attenuation coefficient for air for a photon of energy E, [d.
The mass energy absorption and attenuation coefficients are obtained from the computations of Hubell, 1982 and ICRU, 1994.
d0] is a background value of the diffuse attenuation coefficient and [K.
This relation is used in determining the ultrasonic attenuation coefficient due to surface roughness, keeping all other variables unchanged.
0] is the intensity of the radiation beam before passing through the mat (counts/s), [mu] is the mass attenuation coefficient of the mat ([cm.
XMT allows the non-destructive and quantitative high resolution visualization of internal microstructure, the creation of three-dimensional images and the measurement of the linear attenuation coefficient, thus allowing mineral concentration to be analyzed [Davis and Wong, 1996].