Re: (Anti)Neutrino issues

From: Paola Sala <>
Date: Wed, 21 Aug 2013 17:07:39 +0200

Dear Ali
in addition to what Alberto said:

Quoting from the RELEASE NOTES included in the distribution :
* Only interactions by neutrinos as primary particles are considered.
*Secondary neutrinos do not (re)interact.

*Neutrino interactions are activated in "forced mode" : when a neutrino
*primary particle is requested, the code forces a neutrino interaction to
*occur in the point (or area) defined in the BEAMPOS card

In other words: secondary neutrinos are transported without interactions,
primary neutrinos interact without transport, exactly in the position
defined by BEAMPOS.

For what concerns neutrino production:
Fissions do not generate directly neutrinos, they come from the decay of
fission products. Therefore, in order to transport them you have to
activate the radioactive decays through RADDECAY
****** WARNING ****** the production of neutrinos in beta decays is
treated in an approximate way, do not use it for real neutrino studies.

If you just wish to check that neutrinos are created, you can use muons.

(2) this is strange. Can you please send your input file? Please do NOT
set PART-THRES for neutrinos, otherwise theyr energy will be deposited in
the point where they go below threshold, which is unphysical.

(3) there are conference proceedings describin the model, for instance the
one that is in he RELEASE NOTES:
The use of the neutrino event generator (NUNDIS) must be acknowledged by

     G. Battistoni, A. Ferrari, M. Lantz, P. R. Sala and G. I. Smirnov,
     "A neutrino-nucleon interaction generator for the FLUKA Monte Carlo
     Proceedings of 12th International Conference on Nuclear Reaction
     Varenna, Italy, 15-19 June 2009,
     CERN-Proceedings-2010-001 pp.387-394.

Hope this helps

> Dear Fluka experts,
> I'm simulating neutrino interaction events using the Fluka code. I put a
cylindrical scintillator in front of a mono-directional
> beam of electron anti-neutrino (ANEUTRIE). To make the run process be
possible, I "*undiscarded*" the all 6 types of neutrino/antineutrino
particles via the following card:
> DISCARD -neutrie -neutim -neutrit -aneutrie -aneutim -aneutrit
> The program runs well in most cases. However, there exists some
> misconceptions about what appears in the results:
> (1) The attenuation occures to antineutrinos seems to be "huge"
> compared to the cross sections we already know about its interactions
(see Fig below). This is strictly in contrast to the "users manual"
> that says that electron and muon (anti)neutrinos are produced and
> *
> without*
> interactions. I just know that Fluka "forces" the (anti)neutrinos to >
(1-a) It seems that there is NO working (anti)neutrino production
> in Fluka. For example occuring "Fission" reaction should result in
> secondaries, but I was not able to see anything.
> (1-b) I think the folliwng argument in the user's manual has
> Please calrify what is saying by this:
> "Neutrino interactions however are implemented, but independently from
> (2) Reducing the primary (ANTINEUTRIE) particles' energy to 0.1 GeV, the
program crashes and "erroneously" reports that there exists to many
> errors in the input file.
> (3) In addition to (2), setting the energy to higher values, but also
setting the PART-THR of desired particles to values less than 0.1 GeV
will result to the same erroneous "error"!
> (4) BTW it seems that the documentation about neutrino transport process in
> the Fluka jargon is rather poor. A direct search will result in nothing
more than some papers of cosmic project of the Fluka team.
> Cheers,
> --
> Ali Koosha

Paola Sala
INFN Milano
tel. Milano +39-0250317374
tel. CERN +41-227679148
Received on Thu Aug 22 2013 - 00:01:57 CEST

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