Re: low neutron

From: mojdeh najm <>
Date: Sat, 21 Apr 2012 15:09:18 +0430

Dear Ms.Anna
I set New DEFA with other correction as you told , I tried to decrease the
threshold for electron and photon. please see that and tell me is that
right or does it need extra correction?
In the other hand, I have a question about low-neut card ; you told me
previous setting was wrong in what(1), that means I should select group 72
instead of 260, what 's the reason?
Meanwhile I set Em-cascade without using any extra card in a separate input
file but I got wrong data.
I attached both files for each default. I appreciate you for your helpful
points in advanced.

On Tue, Apr 17, 2012 at 3:16 AM, Anna Ferrari <> wrote:

> Dear Mojdeh Najm,
> I tried to run your input.
> Since you use the defaults NEW-DEFA, which enable the low energy neutron
> transport, FLUKA checks if the low energy cross section tables are present
> for
> every material. Since you have defined praseodymium, which has no library,
> it
> stops. This happens independently on the fact that later on in the input
> you
> swicth off the low energy neutron transport (I saw that you tried two
> methods:
> to stop all the low energy transport via LOW-NEUT + PART-THR -as suggested
> in
> the manual, note 2) under LOW-NEUT - or via LOW-BIAS, where you have put a
> suitable group cutoff in the region that contains praseodymium). You can
> avoid
> the problem with a trick (not elegant, but works). You associate your
> element
> to an element whatever in the library: it is unphysical (I don't like it!)
> but
> you will never use it. I tried to do like that and it works (pay attention:
> what(1) in LOW-NEUT is the number of neutron groups in the cross section
> set
> used... in your input it was wrong).
> Maybe another approch is possible. You have a low-energy (around 2 MeV)
> electron source... defaults EM-CASCA (defaults for pure EM) could be also
> appropriate, you can give a look (there low-energy neutrons are obviously
> off
> by default).
> In any case I would suggest you to check your thresholds for the EM part:
> you
> don't set them, then in the case of NEW-DEFA you get 1 MeV for electrons
> and
> 333 keV for photons, both for production and transport. Maybe you want to
> set
> thresholds more appropriate for your low energy problem via EMFCUT.
> Hope it helps,
> regards,
> Anna
> Am Wed, 11 Apr 2012 02:26:01 +0430 schrieb mojdeh najm <
> >:
> > Dear FLUKA experts
> >> I set NEW- DEFAU with calling LOW-BIAS card but unfortunately I can not
> >> achieve to complete run. I attached my input and flair files, what are
> my
> >> input errors?
> >> regards
> >>
> > Mojdeh Najm

Received on Mon Apr 23 2012 - 09:33:50 CEST

This archive was generated by hypermail 2.2.0 : Mon Apr 23 2012 - 09:33:51 CEST