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)

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