# Dose rate from activation simualtion

Continuing the discussion from Dose rate from activation simulation:

I still agree with you on the explanation you provided above. But I gave deep thought to my simulation, and I still got some questions.

Some neutrons get moderated by the paraffin wax in the central part of the drum, and I would expect the dose rate contribution of gamma-rays following the radiative capture by a hydrogen atom, in addition to the dose rate for the decaying radionuclide. Also, there is neutron leakage out of the drum because not all the neutrons are moderated and attenuated by the material of the drum. As a result, I would expect to get their dose rate contribution.

I considered a simple situation where a neutron source is placed in the drum without metal foil in place, performed a normal simulation (not activation), and I get a high neutron dose rate.
I feel like I am underestimating the dose rates. Can you please clarify this issue?

Thank you

Dear @Motlatsi_Vincent,

in your input file you submitted in the other thread dose-rate-from-activation-simulation you simulate dose rate only after the neutron irradiation has terminated, with decay times of 1 hour and 5.27 years (you probaby expect to see a halving of the dose rate between the first and the second case). After a decay time, there are simply no more neutrons left! (*)
Without decay times, you correctly see neutrons in your scoring volumes.

(*) neutrons have a lifetime of 880 seconds, and you could think that you would score some of the primary neutrons if you define a decay time of 1 second in an activation calculation. This is not the case because only decay radiations from the created radionuclides are tracked in this type of simulation.

Thank you @totto , I understand.