Hi,
I am simulating neutron interaction hitting a piece of lead in my fluka input, I added userdump and then I used the mgdraw file. then in the Linux terminal, I recompiled and linked. I did it before and I had expected results I got different ICODEs including 11 and 14,32. now when I change the number of events from 5 to 10000 my output just has code
example4003.out (79.4 KB)
32 which is really weird., even when I change the event number to the previous number, ICODES 11 and 14 do not appear I am not sure what is the problem, compile and link, or problem is my input file, or my mg draw file. I have attached my file.
I would appreciate it if anyone can help.
example4.inp (2.4 KB)
mgdraw.f (15.6 KB)
Hi,
I have used the attached input file for neutrons hitting a piece of lead, it works well for neutrons with energies higher than 20MeV but it does not give me the expected results for Low energy neutrons do you have any idea what card I should add?
Thanks
neutron_1MeV.inp (2.5 KB)
Dear Razieh,
sorry the late notice, we will have a look at your problem.
Is it intentional that you implement a new definition for lead? Generally, lead is one of the pre-defined materials in FLUKA, so it is not necessary to redefine the material.
I will come back with more answers to the other questions.
Cheers,
Barbara
Thanks,
No, it is not intentional. I thought it was needed to add that card.
Dear Razieh,
the way you linked the user routine and launched your simulation was correct. For using lead, you should remove the MATERIAL card you created yourself and instead only use the pre-defined (LEAD) material for the target.
We had a look at the mgdraw.f routine that you are using, and we came to the conclusion that it is doing what you have told it to do. So first, you have the MGDRAW subroutine, which you use to produce the *_fort.22 file, which gives you the various properties of the particles.
Secondly, (and more crucial) you are also using the ENDRAW subroutine to produce the *_fort.24 files, which writes for every energy deposition codes. Here you expect to see the various ICODE numbers but only see 32 because you are filtering for neutrons but neutrons are generally do not deposit energy in any material, except when they enter into BLACKHOLE. In the code, this is considered as escaping the geometry and therefore the energy deposition there.
For “escaped” particles, you can obtain several codes:
- 14 (called from
Kaskad): this refers to hadrons and muons. Neutrons with energies >20MeV are considered as hadrons. - 23 (called from
Emfsco) refers to electromagnetic particles (electrons, positrons, and photons). - 32 (called from
Kasneu): this number refers to escaping low-energy neutrons, which are neutrons <20MeV.
As your primary neutrons have undergone several inelastic scattering events in the lead block where they lose a significant amount of energy, you only see the ICODE 32 and no 14 in your _fort.24 file.
As stated above, you any neutrons depositing energy. Therefore, we would suggest that you remove the condition for filtering for the neutrons and also allow for other particles. Watch out, as the file most likely will get quite large quickly.
If you have any other questions, do not hesitate to ask.
Cheers,
Barbara
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A post was split to a new topic: Low-energy neutron capture