absorption coefficient
Quick Summary
In physics, absorption is the transfer of a wave's energy to matter as the wave passes through it. This process causes the wave's amplitude to decrease. If a substance absorbs only a small fraction of the energy, it is considered transparent to that radiation; if all energy is lost, it is opaque.1
Substances absorb specific wavelengths of radiation selectively. For example, green glass absorbs red and blue light but is transparent to green light. The extent of absorption depends on the substance's nature and thickness. An absorption coefficient quantifies how much energy a wave loses when passing through a material of a given thickness.1
A related term is the mass absorption coefficient, which is the absorption coefficient divided by the density of the substance. Sound absorption, a specific type of attenuation, occurs when sound waves lose energy to the medium through processes like heat conduction and fluid viscosity. This absorption is often proportional to the square of the sound wave's frequency.23
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- spectroscopyRelation to atomic structure
…it is found that the absorption coefficient changes sharply at X-ray wavelengths corresponding to the energy just required to remove an electron from a specific inner shell to form an ion. The sudden increase of the absorption coefficient as the wavelength is reduced past the shell energy is called an…
Read More…it is found that the absorption coefficient changes sharply at X-ray wavelengths corresponding to the energy just required to remove an electron from a specific inner shell to form an ion. The sudden increase of the absorption coefficient as the wavelength is reduced past the shell energy is called an…
Read More - spectroscopyApplications
…element, small oscillations in the absorption coefficient are observed when the incident X-ray energy is varied. In extended X-ray absorption fine structure spectroscopy (EXAFS), interference effects generated by near neighbours of an atom that has absorbed an X-ray, and the resulting oscillation frequencies, are analyzed so that distances to the…
Read More…element, small oscillations in the absorption coefficient are observed when the incident X-ray energy is varied. In extended X-ray absorption fine structure spectroscopy (EXAFS), interference effects generated by near neighbours of an atom that has absorbed an X-ray, and the resulting oscillation frequencies, are analyzed so that distances to the…
Read More