Attenuation length

This article includes a list of references, related reading, or external links, but its sources remain unclear because it lacks inline citations. Please help improve this article by introducing more precise citations. (January 2010) (Learn how and when to remove this message)

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 63% of the particles have been stopped.

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

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

In general λ is material- and energy-dependent.

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

• S. Eidelman; et al. (2004). Particle Data Group (ed.). "Review of particle physics". Phys. Lett. B. 592 (1–4): 1–5. arXiv:astro-ph/0406663. doi:10.1016/j.physletb.2004.06.001. PMID 10020536. S2CID 118588567.
• https://web.archive.org/web/20050215215652/http://www.ct.infn.it/~rivel/Glossario/node2.html

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

This particle physics–related article is a stub. You can help Wikipedia by expanding it.

• v
• t
• e