Dose 2016

Derivation of formalism to convert ionisation in plastic to dose to water Distance scaling in a clinical beam

(

)

effective mass attenuation coefficients

z

ρµ

eqs,

depth scaling, polyenergetic photon beam:

w

=

(

)

ρµ

z

ref w,

s

  

 

µ

( e Az TPR −  − ρ ) ref zz

( ) ,

Depths in (g/cm 2 )

≈

z

where TPR is

ref

normalised

depth

field size

depth

 

s z        

µ

ρ

z

=

refw, = ⇒ ≈

w

c

z

Depth scaling factor for the clinical beam:

s

eqs,

 

µ

z

c

s

s

ρ

w