Attenuation length

In physics, the attenuation length or absorption length is the distance Template:Mvar into a material when the probability has dropped to Template:Math 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 Template:Math, or about 63% of the particles have been stopped.

Mathematically, the probability of finding a particle at depth Template:Mvar into the material is calculated by the Beer–Lambert law:

$P(x)=e^{-x/\lambda }$.

In general Template:Mvar is material- and energy-dependent.

See also

• Beer's Law
• Mean free path
• Attenuation coefficient
• Attenuation (electromagnetic radiation)
• Radiation length

References

• Template:Cite journal
• https://web.archive.org/web/20050215215652/http://www.ct.infn.it/~rivel/Glossario/node2.html

External links

• http://henke.lbl.gov/optical_constants/atten2.html