Fluence

From Wikipedia, the free encyclopedia

You have new messages (last change).
This article or section is in need of attention from an expert on the subject.
Please help recruit one or improve this article yourself. See the talk page for details.
Please consider using {{Expert-subject}} to associate this request with a WikiProject

Fluence is defined as energy per unit area . Its units are J/m2.

Fluence is a measure of the strength of a radiation field. It is considered the most fundamental unit in dosimetry. It has two equivalent definitions:

1) Imagine that a sphere of small cross sectional area da is impinged upon by dN particles of a certain type. Then, the fluence is:

\Phi = \lim_{{\rm d} a \to 0} \frac{{\rm d} N}{{\rm d} a}.

2) Using the same image of a small sphere as above:

\Phi = \lim_{{\rm d} V \to 0} \frac{\sum {\rm d \ell} }{{\rm d} V},

where dV is the infintesimal volume and \sum {\rm d \ell} is the sum of all the path lengths that transverse the volume.


[edit] References

ICRU 33: Radiation Quantities and Units, April, 1980. (www.icru.org)

 This nuclear physics or atomic physics-related article is a stub. You can help Wikipedia by expanding it.
This medical article is a stub. You can help Wikipedia by expanding it.
Retrieved from "http://en.wikipedia.org../../../f/l/u/Fluence.html"