f is just the normalization factor. It allows you to compute the flux in absolute terms if you know the actual thermal power P. Otherwise, the flux is relative and can be normalized to any arbitrary value.
Does that make sense?
i understand that but in the documentation, it’s only the method how to normalize the flux with f , but what if i want to approach heating or heating-local with f. These tallies are only used to search f ? and the unit of f is “source/s” so if I want to approach heating and heating-local so the final units are eV/s ?