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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
( )
( )
response
,
,
x y
x y
The energy absorption coefficient
m
en
of any buildup
material varies with lateral spectral shifts.
Since primary dose for CPE is very close to
scanning in air could yield results that decribes how the
primary dose will vary laterally!
x.xxx
(
)
(
)
wat
en
,
,
x y
x y
m