Re: [fluka-discuss]: how to tag the region where the first hadronic interaction of a heavy ion takes place?

From: <alfredo.ferrari_at_mi.infn.it>
Date: Fri, 11 Feb 2022 09:14:58 +0100

Dear Enrico

you can tag particles, for example attaching to them a flag reporting the
region of the first interaction.

As an example, if you take the stuprf.f routine (usermvax directory) and
you add the following lines:

....

      INCLUDE '(EVTFLG)'
      INCLUDE '(FLKSTK)'
      INCLUDE '(TRACKR)'
* Start extra lines
* *-------------------------------------------------------------------*
* | First generation (Ltrack=1) nonelastic interaction (Linevt) or
* | ElectroMagnetic dissociation (Leldis): save inside Louse the
* | region number of the interaction, it will be propagated inside
* | the Llouse (TRACKR common) variable to all following generations
      IF ( ( LINEVT .OR. LELDIS ) .AND. LTRACK .EQ. 1 ) THEN
         LOUSE (NPFLKA) = MREG
* |
* *-------------------------------------------------------------------*
* |
      ELSE
         LOUSE (NPFLKA) = LLOUSE
      END IF
* |
* *-------------------------------------------------------------------*
* End extra lines
      DO 100 ISPR = 1, MKBMX1
....

all secondary particles when propagated will have inside the LLOUSE
variable (common TRACKR) the region number of the first interaction, and
then you can apply whichever selection when recording the hits according
to that variable.

I hope this helps

Alfredo



> Dear Fluka team,
>
> let me ask your support for a problem I am currently facing.
>
> I have a (complex) experimental set-up and I am shooting a beam of 40A
> GeV Pb ions that impinges on a system of 5 Pb targets, for a total of
> 15% interaction probability. The remaining Pb ions that do not perform
> an inelastic interaction continue travelling and are then dumped in a
> thick W plug.
>
> I would like to be able to select those events where the first inelastic
> interaction of the Pb beam occurs in one of the 5 targets, and only for
> those events record the hits in the downstream tracking detectors. I
> already now record such hits by means of a few lines of code in the
> BXDRAW entry, but for all events regardless of the interaction point of
> the Pb ion. See the zoom drawing below, where one can see on the left
> the 5 targets (REGION Target0, Target1,....) and on the right the plug
> (REGION AbsoPlug).
>
> Any help would be welcome! I can of course provide more info if needed.
>
> Best regards
>
> Enrico
>


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Received on Fri Feb 11 2022 - 10:36:34 CET

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