Re: [fluka-discuss]: How to extract the neutrino cross sections, as a function of neutrino energy?

From: Andrea Celentano <andrea.celentano_at_ge.infn.it>
Date: Tue, 3 Oct 2017 18:09:52 +0200

Dear Bei,
this is the way I am extracting this information from Fluka. I followed
what suggested here:
http://www.fluka.org/web_archive/earchive/new-fluka-discuss/8808.html

In my simulation, as you do, I have an input spectrum for neutrino
energy, and I write a source.f routine to sample primary neutrino energy
from this.
I used LFRPHN (NPFLKA) = true to force primary neutrino interaction in
the point I create it.

Then, I have a user mgdraw.f routine, where the USDRAW entry looks like:

     if ((JTRACK .eq. 27).or.(JTRACK . eq. 28).or.(JTRACK.eq.5)
      &    .or.(JTRACK.eq.6)) THEN
             CALL eventCreate(NCASE,JTRACK,ETRACK,CXTRCK,CYTRCK,CZTRCK,
      &     XSCO,YSCO,ZSCO,WTRACK,WSCRNG)
             CALL eventxsection(ICODE,STNUSC,OPACTY)
             CALL eventSave
         end if

What I am doing here is to save, for each event, the energy of the
neutrino ETRACK and the two variables STNUSC and OPACTY defined in
(NUINFO) and (NUCGEO) commons

(eventCreate, eventxsection, eventSave are 3 routines that are writing
this data in a ROOT file, you can simply write them to a txt file)

After the simulation, I am processing my data file to extract the cross
section as follows:

* I have a first histogram, h1, where x-axis is neutrino energy, that I
fill, for each saved event, with x=ETRACK, giving it the weight STNUSC
* I have a second histogram, h2, where x-axis is the neutrino energy,
that I fill, for each saved event, with x=ETRACK, giving it the weight
1./OPACITY

* I define a third histogram, h3, as h1 / h2 -> This histogram contains,
in each bin, the neutrino cross-section at that bin energy (in pbarn)

Bests,
Andrea

On 10/03/2017 05:07 PM, Bei Zhou wrote:
> Dear FLUKA users,
>
>
> Does anyone have a good way to extract the neutrino cross sections, as
> a function of neutrino energy?
>
> I am simulating neutrino interaction with water by FLUKA.
>
> However, according to FLUKA release notes:
>
> "With this beta release, the use of an user-written source for
> neutrino interactions is possible, provided the following card is
> added when a neutrino is loaded on the stack: LFRPHN (NPFLKA) = .TRUE.
> In this way, the neutrino will then be *forced* to interact at the
> point specified as starting position in the source routine. In case a
> spectrum of energies is input, it is the user task to properly *weigh
> the spectrum with the relevant neutrino cross sections*"
>
>
> Thanks!
>
> Best,
> Bei
>




__________________________________________________________________________
You can manage unsubscription from this mailing list at https://www.fluka.org/fluka.php?id=acc_info
Received on Tue Oct 03 2017 - 19:23:16 CEST

This archive was generated by hypermail 2.3.0 : Tue Oct 03 2017 - 19:23:17 CEST