I am new to OpenMC and i was wondering how can i get the total heating produced in my geometry. I’ve seen that the ‘heating’ tally gives the values in eV/source. How can i get the energy in J or even the power in Watts ? I believe i need to know the number of source particles but i am not sure if it is the same as the number of particles i use to run the simulation.
Hello!
You’ve got the units units correct. In an MC code like OpenMC, all the tallies are per source particle. This means that how you interpret the results depends on how you interpret the source particle situation.
For example, if you assume there are 10 source particles per second, that would imply that multiplying the number you calculated by 10 would give the heating rate in eV/s.
Similarly, if you assumed that some radioactive source emitted 1000 particles, regardless of time, multiplying the heating tally by 1000 would give the total eV of energy deposited in the problem.
The results will always be normalized to a per source particle basis, so changing the total number of particles you run will not affect how you interpret the results. You’ll just have lower variance.
To get the power in other units, you need to make an assumption about the number of particles per second for the problem of interest, then convert from eV/s to watts or similar.
Good luck!
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Thank you very much for your explanation ! It really helps.