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Linear attenuation coefficient
Describes attenuation of a photon beam
Torikoshi
et al
:
•
ρ
e
=
ρZ/A*N
A
= electron density
•
Z =
effective atomic number
•
F
(
E,Z
) and
G
(
E,Z
) are the photoelectric absorption and scattering
terms (Rayleigh and Compton) of
μ
For polychromatic x-rays:
x-ray spectra represented by weights
ω
i
at
E
i
(
)
) , (
)
, (
)
(
4
ZEG Z
EF
Z E
e
+
=
) , ( ) ,
(
4
ZEG ZEFZ
ji
ji
i
ji
e
j
+
=
Torikoshi et al, Phys. Med. Biol. 2003; 48: 673-685.
Tsunoo T, et al , NSS Conference Record, IEEE, 2004; 6: 3764-3768