Law of absorption (physics)

This article deals with the law of absorption in physics. In mathematics, the validity of absorption laws is characteristic of associations , which also include Boolean algebras .

The law of absorption for photon radiation ( X-rays , gamma rays ) in a homogeneous material has the same exponential form as the law of decay . The number dN of the photons absorbed in a thin layer (thickness dx ) at the penetration depth x per unit area is proportional to the particle flux density N (x) of the radiation still present there :

${\displaystyle {\frac {dN}{dx}}=-\mu N(x)}$.

The solution to this differential equation is

${\displaystyle N(x)=N(0)\cdot e^{-\mu \cdot x}}$

Here is the absorption coefficient, which depends on the material and the photon energy . ${\displaystyle \mu }$

literature

• Dieter Meschede: Gerthsen Physik , Springer, 24th edition 2010, ISBN 978-3-642-12893-6 , pp. 179, 945

See also

• Lambert-Beer law