I understand the neutron tally normalization factor of Pnu/(Qk) discussed here.
My question is: in a coupled neutron-photon criticality calculation, while normalizing the photon tallies, do I need to use the same factor, including the division by k-effective?
I am asking this, because the machinery of neutron and photon production is quite different in OpenMC. The neutrons are followed from the current to the next fission reaction, while photons are created statistically per nuclide interaction.
I think that normalizing by P*nu/Q/k needs k in it because in this form nu is taken from the calculation, and in order to get the “real” nu you need to scale it by k (such as defined in the transport equation). The Q that appears here is in [J/fission] and is many many times taken from experiment, or just taken as 200 MeV, because it is not such a sensitive number.
On the other hand, when normalizing as explained in Section 8.3, you directly calculate the value of H’ [J/source] through the “heating” tally. So the normalization factor is just P/H’. This way, you don’t need to go through fissions or through neutrons produced, and directly get the source neutrons that are needed for normalization.
I am not exactly sure if this is correct, but this is my understanding.