Quick question:
How does openmc calculate a flux score on a cell filter?
I’m wondering how it handles calculating something that has units of per area^2 using a filter that has volume.
Let me know if I can clarify.
Thanks,
Luke
I think that in this case adding a cell filter dosn’t changes the units of the tally, it just restricts scoring region. Although some filters like the EnergyFunctionFilter do change the units of the tally, I believe that cellFilter doesn’t. So the tally will still be in the normal flux units.
The equation at the bottom of this page might be helpful as it has flux and volume units in an example post process calculation.
Also just to advertise a openmc_tally_unit_converter package I’ve been working on that attempts to convert the base tally units to the units required as I happen to have a similar example
example for flux processing with volume
@LukeLabrie A flux tally has units of [particle-cm/source]. The [cm] in the numerator you can think of as representing the integrated tracklength of particles through a cell. Note that using a cell (or other spatial filter) doesn’t change the units of the tally, only the volume over which scoring events are integrated. If you want a flux in [particle/cm²-source], you just need to divide by the volume of the cell in question, and if you want the flux in conventional units of [particle/cm²-sec], you need to account for the source rate in [source/sec].