Search results
Results From The WOW.Com Content Network
The mass attenuation coefficient (also called "mass extinction coefficient"), which is the absorption coefficient divided by density; The absorption cross section and scattering cross-section, related closely to the absorption and attenuation coefficients, respectively "Extinction" in astronomy, which is equivalent to the attenuation coefficient
The absorption coefficient of a volume, denoted μ a, and the scattering coefficient of a volume, denoted μ s, are defined the same way as the attenuation coefficient. [ 6 ] The attenuation coefficient of a volume is the sum of absorption coefficient and scattering coefficients: [ 6 ]
A common expression of the Beer's law relates the attenuation of light in a material as: =, where is the absorbance; is the molar attenuation coefficient or absorptivity of the attenuating species; is the optical path length; and is the concentration of the attenuating species.
In an optical context, the absorption spectrum is typically quantified by the extinction coefficient, and the extinction and index coefficients are quantitatively related through the Kramers–Kronig relations. Therefore, the absorption spectrum can be derived from a scattering or reflection spectrum.
Optical depth of a material is also related to its attenuation coefficient by: = (), where l is the thickness of that material through which the light travels; α(z) is the attenuation coefficient or Napierian attenuation coefficient of that material at z,
The absorption was attributed to a sequence of overtone and combination bands whose intensity decreases at each step, giving rise to an absolute minimum at 418 nm, at which wavelength the attenuation coefficient is about 0.0044 m −1, which is an attenuation length of about 227 meters. These values correspond to pure absorption without ...
The SI unit of molar absorption coefficient is the square metre per mole (m 2 /mol), but in practice, quantities are usually expressed in terms of M −1 ⋅cm −1 or L⋅mol −1 ⋅cm −1 (the latter two units are both equal to 0.1 m 2 /mol).
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 ...