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Particles – Effective Energy
Example:
β
-
decay of
137
Cs Photons
For dosimetric purposes it is more appropriate to consider the effective energy E
eff
Characteristic
651.8keV
Ef
E
i
E ,
tr
i
i
2
i
eff
=
µ
ρ
µ
⋅
⋅
=
α
∑
∑
defined as the air-kerma weighted mean energy. This is given by:
i t
γ
-rays
E
i
f
i
Ef
i
E ,
tr
i
i
i
ρ
⋅ ⋅
α
is the mass energy transfer coefficient
for photons of energy E
i
in air.
i
E ,α
tr
ρ
μ