Attenuation length

Particle penetration depth at which the likelihood of non-absorption is 1/e

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:

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

In general λ is material- and energy-dependent.

See also

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

References

  • 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

External links

  • http://henke.lbl.gov/optical_constants/atten2.html
  • v
  • t
  • e