CPB Budapest 2017

Particles – Effective Energy

Example: β - decay of 137 Cs Photons

For dosimetric purposes it is more appropriate to consider the effective energy E eff

defined as the air-kerma weighted mean energy. This is given by:

∑

  

  

µ

2

tr

⋅

⋅

Ef i

i

ρ

i t

α

E ,

i

i

=

=

E

651.8keV

∑

eff

  µ

tr

  ρ ⋅ ⋅

Ef

 

i

i

α

Characteristic

E ,

i

i

γ -rays

is the mass energy transfer coefficient for photons of energy E i in air. i E ,α tr ρ μ      

f

E

i

i