Dose Course 2018_Flipping book
Beam energy spectra Unfolding measured transmission data
Variable thickness attenuator
Detector
E
x
Narrow beam
Treatment head
Secondary collimator
( S x
)
E
max
( ) − m
E x
( )
R E
E
e
d
( R E
)
Detector response
E
General:
( ) ( ) 0
S x S
0
=
E
max
Energy fluence spectrum
( ) R E E d E
E
0
( ) i − m
E x
( ) j
S x
E
S =
A
=
e
j
Simple approach: (neglects energy response variations)
E
i
j
, i i j
i
i
i
to be solved by numerical methods (linear algebra)
27
Made with FlippingBook HTML5