Dose Course 2018_Flipping book

More about transport along a line…

Factorization of attenuation:

 i



L

=

i

i



a

−

i

3 e e e ... − − 1 2 a a a −

a

−

aL

−



e e =

=

=

e

L

i

i

i

Transport of radiant energy along line:

a − 

i i R R =

e

R D

+

i

i

−

1

Net energy release from a step  i

(“collapsed” solid angle D W, kernel= A e - a  :

i

A

A

(

)

(

)



a − 

−

a − 



R T

T =  

D

=  

 DW 

e

d

 DW 

1 e −



i

i

i

i

i

i

i

2

a

a

attenuation from point

0

energy release



of release to exit at

per length

i

R R +

i

i

−

1

D a 

Local dose absorption:

21

i

2