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Spectrum corrections of raytraced collision kerma
and scerma for attenuated beams (wedges)
Multiply cKERMA by
Multiply SCERMA by
(
)
(
)
PQ
0
0
ˆ
mod
P
P
k
open
=
5
10
15
20
25
30
Depth in water [cm]
0.90
0.95
1.00
1.05
1.10
Beam quality corrections for a 1.5 cm lead attenuator
k
PQ,
k
SQ
0
0
4MV, k
PQ
4MV, k
SQ
24MV, k
PQ
24MV, k
SQ
(
)
(
)
(
)
(
)
(
)
1
KERMA
mod
,
1 KERMA
open
PQ
g
depth thickness
g
k
−
=
−
(
)
(
)
(
)
SCERMA
mod
,
SCERMA
open
SQ
depth thickness
k
=
i. e.
Where is the modulation.
ˆ
(
)
(
)
SQ
0
0
ˆ
mod
S
S
k
open
=