Dear Paola,
Thank you so much for identifying the problem! I changed the variable to
ID and it indeed got rid of the weird dE/dx problem.
Thank you very much!!
Shirley
On Sat, Jul 14, 2018 at 9:51 AM, Paola Sala <paola.sala_at_mi.infn.it> wrote:
> Dera Shirley,
> There is one possible answer, please check and let me know if the problem
> persists:
> In the source.f, momentum and kinetic energy are not consistent: In the
> kinetic energy, the mass of your selected particle is used (ID) , but in
> the momentum calculation, the mass is the one of "IONID" that is set by
> default to the primary in the BEAM card (a muon in your case.)
>
> The effect is unpredictable. (maybe we'll introduce a check..)
>
> TKEFLK (NPFLKA) = ENEGY - AM(ID)
> * Particle momentum
> c PMOFLK (NPFLKA) = PBEAM
> PMOFLK (NPFLKA) = SQRT ( TKEFLK (NPFLKA) * ( TKEFLK (NPFLKA)
> & + TWOTWO * AM (IONID) ) )
>
>
> Regards
> Paola
> > Dear FLUKA users,
> >
> > I am studying particle propagation in liquid argon. When I look at
> proton
> > energy loss, DTRACK in mgdraw, I thought it should be ~= CTRACK * dE/dx
> > rate. While this seems true (with fluctuations) for almost all proton
> > tracks, occasionally I get very large DTRACK, compared to CTRACK * dE/dx.
> > For example, for the input attached below, I get the following examples:
> > ncase jtrack etrack ptrack z0 z1 ctrack
> > dtrack
> > 25.0 1.0 1.009945 0.373675 0.0 0.768607 0.785268 0.229055
> > 37.0 1.0 0.961867 0.211738 0.0 0.037436 0.127902 0.118133
> > 43.0 1.0 0.968080 0.238378 0.0 0.052170 0.193938 0.137920
> >
> > KE dEdx ctrack*dE/dx
> > 0.071672 0.009352 0.007344
> > 0.023595 0.022066 0.002822
> > 0.029808 0.018381 0.003565
> >
> > Here the dEdx rate is interpolated from FLUKA output .out file for
> > protons. These protons are not near boundary or anything. And the
> dtrack
> > is not only longer than ctrack*dE/dx, but they are also larger than the
> > proton kinetic energy. So I'm not sure if I misunderstand what DTRACK
> > means. Does anyone understand this?
> >
> > My inputs attached below. The source file is user-defined because I'm
> > injecting secondary particles coming out of another generator. I cannot
> > reproduce this behavior when I just inject primary protons in FLUKA.
> >
> > Thank you very much!!
> >
> > Shirley
> >
>
>
> Paola Sala
> INFN Milano
> tel. Milano +39-0250317374
> tel. CERN +41-227679148
>
>
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Received on Fri Jul 20 2018 - 02:59:59 CEST