Mo production in FLUKA and fission yield plot

[riya]

Dear Experts,

I intended to reproduce the results presented in this post http://www.fluka.org/web_archive/earchive/new-fluka-discuss/att-2506/Burgio-99Mobyfission_FLUKA.pdf

Along with that, I wanted to to generate double hump fission product yield curve.

I looked into other posts and tried to create the input. But I got errors while running saying low energy xsec not found for some media, I tried to add LOW-MAT card, but it showed error option. I am unable to understand that. I am not sure if there are other mistakes in the input.

Can you please guide ?

Regards,

Riya

[amario]

Can you please share your input?

[riya]

Hi @amario ,

I am soo sorry that I forgot the attachments. Here they are :

Mo_prod.inp (2.4 KB)
source_newgen.f (18.7 KB)

Regards,
Riya

[adonadon (Andre Donadon Servelle)]

Dear @riya,

Thanks for your question.

I saw your input file and I found the following errors.

In the input file I attached here:
Mo_prod_ads.inp (2.5 KB)

I redefined a few regions with some mistakes.
In your input file, you had this situation, with many regions overlapped:

And now it is looks like this:

Look at the difference between both input files, and if you have any doubts, let me know.

2. As you said, you have to add the low-mat card. I can run the simulation with the LOW-MAT card that I added in the input I send you, thus It should work for you as well.

I hope this helps. In case you have more problems, do not hesitate to ask again.
Have a nice day,

André

[riya]

Hi @adonadon ,

I tried to run your input. I have not modified anything, only added the history. But it got run time error.

Regards,
Riya

Mo_prod_ads.inp (2.5 KB)
source_newgen.f (18.7 KB)

[adonadon (Andre Donadon Servelle)]

Dear @riya,

I think I found the issue.

If you go to your source_newgen.f:

You are providing a value of momentum of 10^{-9} GeV

• First, the exercise says 0.1eV → 10^{-10} GeV
• Second, the value is, from what I saw in your exercise, for the kinetic energy.

There is a flag in source_newgen.f (energy_logical_flag) where you can define the “momentum_energy”
as kinetic energy.

I send you the inputs with the changes:

Mo_prod_ads_lv.inp (2.5 KB)
source_newgen_ads.f (18.7 KB)

This should solve the problem.

Cheers,
have a nice weekend

André

[riya]

Thank you @adonadon for the guidance. I gave a run of your input with 1E+6 histories with 10 spawns. It is showing a 34 days of run completion time. Is it normal in case of activation product simulation ?? Or, what is the typical history (if any) normally used in activation product simulation ?

Regards,
Riya

[adonadon (Andre Donadon Servelle)]

Dear @riya,

I tested the input with the same amount of primaries and I have a similar runtime.
But, for the purposes of your simulation you do not need to have low cutoffs.
I suggest you to increase the cutoffs in the EMFCUT card and you will observe how this reduces drastically the runtime.

cheers,
André

[amario]

Additionally, you can act on the transport thresholds for the prompt and decay parts separately, see the activation lecture from the last Fluka course.
With the RADDECAY card (slides 18 and 19) you can increase the transport threshold for the prompt part, while leaving the decay part threshold lower.