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Radiant energy transport along a transport line
• Performed separately for primary and scatter dose
Analytical raytrace of kernel exponential through
a voxel constitutes a transport step of the
radiant energy:
out
( )
R
=
attenuation of
incoming energy
in
e
a
R
−
radiant energy contribution from the
voxel considering intravoxel attenuation
(
)
2
1 e
a
k
a
−
+
−
Energy deposited inside the voxel (appr.
a
.
R
) becomes
the
deposited dose
• Parameter
a
.
from kernel parameterization (water) is scaled
to represent the voxel medium,
k
stems from incident beam
energy release (coll KERMA and SCERMA) and medium
out
R
in
R
( )
2
e
e
,
a r
b r
A
B
h r
r
−
−
+
=