Compton scattering in MCNP

[Salman Khan]

I am interested to find the electron yield of a material like Aluminium by incident photon of energy let say 2 Me. I used
Mode p e
And tally
F11: e accros desired surface
F21: p across desired surface
only to find its value. Is it necessary to use phy card as well or no need of it. Thanks in advance

 

[Alex A]

It depends on exactly the question you want to answer, but incoherent (Compton) scattering is special reaction number -1 for photons. So the following UNTESTED tally might work for the total number of Compton events per source photon.

f4:p <cell number>
sd4 1.0 $ Not the per unit volume answer. The total.
fm4 -1 <material in the cell> -1

 

[Salman Khan]

Basically I want to find the electron yield of Au-79 by incident gamma photon of energy 2 Mev using point gamma source. Here if I use mode p e and if i use tallis F11:p (incident photon on front plate of AU-79) and F21:e (emitted electron by Au-79 due to incident photon). Yield=F21:e/F11:p. My sdef card will be like
Sdef Erg=2 parr=2 pos=0 0 30
m1 79000 -1
m2 air composition
Mode p e
Nps 1000000
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