Dear Carl Ross
thank you for your kind appreciation of Fluka/Flair. Looks like the only
problems are in the documentation -)
Let me use your post to add/recall a couple of things:
- The "no ran002g enerated" error is a general one, it occurs every time
the code stops because of an internal check. The "real" error is reported
at the end of the xxx001.out file:
**** Low energy neutron xsec not found for some media
Mo100
==> always look inside the fluka output file. And, yes, somentimes the
error message is difficult to understand,...but it is there.
More than this, the output file contains an echo and an INTERPRETED echo
of the input, very useful to double check settings and scorings
- LOW-MAT: is necessary if the new material name is not in the list of
the low energy neutron data sets, as available in the manual. It is true,
one needs low-mat only if neutron transport is requested. The point is
that neutron trasport is requested by default..and by most DEFAULTS,
except EM-CASCA. Just because once a neutron is produced..much better to
transport it, there are really a minimal set of problems where low energy
neotrond can be discarded.
- PHOTONUC (not in your question, but in your input.. ) "Because
photonuclear cross sections are much smaller than photon cross sections
for electromagnetic interactions with atoms and electrons, analogue
simulations of photonuclear interactions are very inefficient. Generally,
it is recommended to use PHOTONUC in combination with LAM-BIAS to increase
artificially the frequency of photonuclear interactions"
Regards
Paola
> Re: failure of Fluka/Flair to trap a missing component in the input file.
>
> I am working on a problem where I need to define a new material, namely
> mono-isotopic Mo-100.
>
> Flair reported no problems with the input file but each time I would
> attempt to run it, Fluka would report that it could not write a file
> related to the random number seed:
>
> No rantest1002 generated!
>
> I continued to reduce the input file to a simpler form (attached) still
> with no success.
>
> Through trial and error I discovered that one must define a LOW-MAT card
> for a new material even though neutron transport is of no interest.
>
> Perhaps this point could be emphasized in the documentation if it cannot
> easily be caught by Flair. (Note 7 under MATERIAL in the user manual is
> relevant, but it suggests LOW-MAT is only needed if neutron transport is
> of
> interest).
>
> My conclusion (based on limited evidence) is that, if you define a new
> material, you must deal with LOW-MAT.
>
> Also, anything that could lead to a more meaningful error would be very
> helpful.
>
> In general, Fluka/Flair is an impressive software package,
>
> Carl Ross
>
Paola Sala
INFN Milano
tel. Milano +39-0250317374
tel. CERN +41-227679148
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Received on Mon Jan 25 2016 - 13:04:21 CET