Tallying in Energy Units and Using CollisionFilter

User Support
1

Hi All,

I have some basic questions related to tallying. Apologies if these are in the documentation already, I looked but still wasn’t sure about these.

  1. Is there a way to get fluxes/currents in energy units (i.e. MeV/cm^2 and MeV), similar to MCNP’s *Fn flag? I can envision doing this manually with an EnergyFunctionFilter, but if there’s a built in way, that would clearly be better.

  2. I’m also interested in tallying only uncollided particles from my source in a fixed source calculation. I believe the way to tally uncollided particles would be using a CollisionFilter([0]), does that seem correct?

  3. Related to #2, are secondary particles considered “uncollided” by default, like in MCNP? Can you toggle that treatment so that secondary particles are not considered uncollided?

As always, thank you for the help!

2

The only way to do this would be to use an EnergyFunctionFilter with two points (one for 0 eV and another for some arbitrary maximum energy, e.g. 100 MeV).

That is correct.

Yes, secondary particles are treated as uncollided. Right now we don’t have a toggle for this but it wouldn’t be difficult to add one and I can definitely see the value in having that.

3

Thank you @paulromano!

4

@paulromano this is an old thread, but I’m wondering if a toggle to treat secondary particles as collided instead of uncollided was ever added? This would definitely be useful!

5

Hi everyone,
Like you alex, I would be very interested in this feature ! Is there anything new on this ?
Thanks in advance :slight_smile: