Separate the inelastic and capture reactions in a tally

[Alexander Camargo]

Hello everyone. I have a 14 MeV neutron source and a gamma photon detector at a distance. This detector is for counting photons from inelastic reactions and capture.
How do I configure a tally to output only inelastic and capture reactions separately?

 

[Alex A]

Do you need a count, or do you need an energy spectrum?

Edit, these might be solved the same way - with an fm card. Say you used an f4 tally with the detector containing material 3. Then,
fm4 -1 3 102
Would modify the tally to produce the result for (n,gamma) capture events.
Where,
fm4 -1 3 2
Would modify the tally to produce the result for elastic scattering events.
102 being the ENDF/B capture reaction type and 2 being the elastic cross section reaction type.

 

[Alexander Camargo]

Do you need a count, or do you need an energy spectrum?

Edit, these might be solved the same way - with an fm card. Say you used an f4 tally with the detector containing material 3. Then,
fm4 -1 3 102
Would modify the tally to produce the result for (n,gamma) capture events.
Where,
fm4 -1 3 2
Would modify the tally to produce the result for elastic scattering events.
102 being the ENDF/B capture reaction type and 2 being the elastic cross section reaction type.

Got it. I'm using tally F4. My intention is to calculate the sigma of a given material. I need to separate only the part of the spectrum that comes from capture reactions. In this case, the detector isn't the target material; I need to calculate the material that interacts with the beam, and only then will the detector calculate it. I'll try it out. Thank you very much.

 

[Alexander Camargo]

Do you need a count, or do you need an energy spectrum?

Edit, these might be solved the same way - with an fm card. Say you used an f4 tally with the detector containing material 3. Then,
fm4 -1 3 102
Would modify the tally to produce the result for (n,gamma) capture events.
Where,
fm4 -1 3 2
Would modify the tally to produce the result for elastic scattering events.
102 being the ENDF/B capture reaction type and 2 being the elastic cross section reaction type.

I don't think the reaction number is 102. I simulated it and got this error: "fatal error. Illegal photon reaction number, 102, on FM 24 card."
Is there a reference to where I can find this table?

 

[Alex A]

Oh, is the detector a gamma detector? Not a neutron detector?
You want photoelectric events and Compton events?
Or was the tally supposed to be a neutron tally?