Hi freinds,

I see in articles that I should report uncertainties. but I don’t know what should I do in geant4.

I used root for my results.

Please guide me if you have any ideas.

That depends on what you are simulating, how many particles you simulated, what your results are, etc.

for my simulation, the total number of primary particles is 10^8. my results are dose deposition graphs.

I read somewhere in internet that we can divide standard deviation/sqrt(N) to get global uncertainties. I don’t know whether it can be applied here or not.

I think it is useful to be careful about the language here.

From a typical Monte Carlo simulation you extract the frequency of quantities. The statistical error of that number, N, is typically sqrt(N) if you assume poisson statistics which applies to most cases.

So, for a energy measured 100 times, you may report is as 100+/-10.

Now, a potentially more interesting question is what is the error of the simulation? For that you may want to run your simulation changing the random seed and get a new result… maybe the same quantity as before now is 90+/-9.5. Now you can do error propagation and get a combined uncertainty.