Advanced Physics for Brachytherapy 2018

The method

➢ We can truncate the expansion of μ s up to N (N=3 is adequate for 192 Ir anisotropic scattering)

N

=

3





 + = → n 

1 2

) ˆ ˆ, E Ers

ˆ( )



,(

,( ,

), ˆ   →

nPE Erns



n

=

0 4

1





=→ E Erns

nP E Ers

d



,( ,

,( 2/1 ) 

)ˆ ˆ,  →

   

)ˆ ˆ( )ˆ ˆ(

 −

1

Note that truncation pertains to the detail in the description of scatter cross section in terms of the scattering angle and that we have NOT discretized in direction