en>BD2412: /* Properties */Fixing links to disambiguation pages using AWB

2014-08-19T13:48:57Z

Properties: Fixing links to disambiguation pages using AWB

en>Denniss: File renamed: File:Baker.webmhd.webm → File:Baker.webm

2013-08-03T13:15:42Z

File renamed: File:Baker.webmhd.webm → File:Baker.webm

← Older revision		Revision as of 15:15, 3 August 2013
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	~~I am Thomas from Winkl. I am learning~~ to ~~play~~ the ~~Post horn~~. ~~Other hobbies are Baking~~.<br><br>Review ~~my blog post:~~ [http://~~Www~~.~~cdhwbg~~.~~com~~/~~plus~~/~~guestbook~~.~~php FIFA Coin Generator~~]		In physics, the '''radiation length''' is a characteristic of a material, related to the energy loss of high energy, electromagnetic-interacting [[elementary particle\|particles]] with it.

			==Definition==
			High-energy [[electrons]] (>~10 MeV) predominantly lose energy in matter
			by [[bremsstrahlung]], and high-energy [[photons]] by {{SubatomicParticle\|Antielectron}}{{SubatomicParticle\|Electron}} pair production. The characteristic
			amount of matter traversed for these related interactions is called the radiation length {{math\|''X''<sub>0</sub>}},
			usually measured in g·cm<sup>−2</sup>. It is both the mean distance over which a high-energy
			electron loses all but {{math\|{{frac\|1\|[[e (mathematical constant)\|''e'']]}}}} of its energy by bremsstrahlung, and {{frac\|7\|9}} of the mean free
			path for pair production by a high-energy photon. It is also the appropriate scale length for describing high-energy electromagnetic cascades.

			The radiation length for a given material consisting of a single type of nuclei can be approximated by the following expression:<ref>{{cite book\| last=Eidelman\| first=S.\| title=Review of Particle Physics}}</ref>

			<math>X_0 = \frac{716.4\cdot A}{Z (Z+1) \ln{\frac{287}{\sqrt{Z}}}}\;\mathrm g\cdot \mathrm{cm}^{-2} = \frac{1432.8\cdot A}{Z (Z+1) (11.319 - \ln{Z})}\;\mathrm g\cdot \mathrm{cm}^{-2}</math>,

			where {{math\|''Z''}} is the [[atomic number]] and {{math\|''A''}} is [[mass number]] of the nucleus.

			For electrons at lower energies (below few tens of [[MeV]]s), the energy loss by [[ionization]] is predominant.

			While this definition may also be used for other electromagnetic interacting particles beyond [[lepton]]s and photons, the presence of the stronger [[strong interaction\|hadronic]] and [[Nuclear_force\|nuclear interaction]] makes it a far less interesting characterisation of the material; the [[nuclear collision length]] and [[nuclear interaction length]] are more relevant.

			Comprehensive tables for radiation lengths and other properties of materials are available from the [[Particle Data Group]]
			<ref>{{cite web\|title=AtomicNuclearProperties on the Particle Data Group\|url=http://pdg.lbl.gov/AtomicNuclearProperties}}</ref>
			<ref>{{cite journal\|author=S. Eidelman et al.\| title=''Review of particle physics''\| journal=Phys. Lett. B\| volume=592 \|year=2004}} (http://pdg.lbl.gov/)</ref>

			==See also==
			* [[Mean free path]]
			* [[Attenuation length]]
			* [[Attenuation coefficient]]
			* [[Attenuation]]
			* [[Range (particle radiation)]]
			* [[Stopping power (particle radiation)]]
			* [[Electron energy loss spectroscopy]]

			==References==
			{{Reflist\|2}}

			[[Category:Experimental particle physics]]

			{{particle-stub}}

en>Linas: see also Bernoulli process

2012-07-30T02:34:49Z

Baker's map - Revision history

en>BD2412: /* Properties */Fixing links to disambiguation pages using AWB

en>Denniss: File renamed: File:Baker.webmhd.webm → File:Baker.webm

en>Linas: see also Bernoulli process