916-917 / 2239
In air scanning of lateral profiles
The signal scored by a scanned detector is directly proportional
to the energy fluence only if the spectrum is constant!
Signal is proportional to
( )
( ) ( )
a
en
m
,
,
,
s x y
x y
x y
µ
Ψ
ρ
⋅
⋅
The energy absorption coefficient
µ
en
of the buildup
material varies with lateral spectral shifts.
20
Since primary dose for CPE is very close to
(
µ
en
/
ρ
)
.
Ψ
,
scanning in air yield results that decribes how the
primary dose will vary laterally!
x.xxx