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A Ahnesjö and P Andreo (1989) Phys Med Biol 34, 1451-64. A Ahnesjö et al (1992) Med Phys 19, 263-273
pencil kernel determination:
Beam modelling refresher: spectrum determination to make a polyenergetic
kernel from a library of Monte Carlo generated monoenergetic kernel:
( ) ( ) ( ) electron cont
1 2 1 2 fsize depth, fsize ebin 1 2 depth, fsize, ebin depth 1 2
fsize depth ebin
, ..., , ... c , ... , ... s s e e D s s d d e e  
   
= −  +
   
   
 
Measured depth dose,
phantom scatter normalized
Spectrum model, constrained
to a “physical” shape
MC calc depth doses for
monoenergetic photons
Electron contamination
model
Error norm to minimize by
varying parameters