Re: [fluka-discuss]: Questions about fluka

From: Answers <>
Date: Mon, 24 Feb 2020 14:21:10 +0100 (CET)

Dear Silvia,
from your image I see that you set "C. Graphite bound nat. Carbon, 296 K",
in the LOW-MAT card.
Please change it with "C. Free gas natural Carbom, 296K".
Indeed, Graphite is declared as having the cross section of Graphite
bound natural Carbon, while diamond is declared as having the same
low-energy neutron cross section as Free Gas Carbon.

Moreover, in the Material card you should leave the Am definition empty.

Regarding the results, if you are modelling a thick target, in which
protons are stopped, I do not expect you to see significant differences
between carbon and diamonds.
Otherwise, you should see some difference due to the different densities
between the two targets.

I hope this helps.

On Thu, 20 Feb 2020, silvia palomba wrote:

> Thanks for the answers but I still have a problem with diamond target declaration.
> I entered a diamond material and  LOW-MAT card, as you told me, I show it in the attachment,
> but the energy deposition of protons, scores through DETECT card,
> for diamond target is equal at the energy deposition of the same protons for carbon target.
> What am I doing wrong?
> Il giorno ven 14 feb 2020 alle ore 10:44 Paola Sala <> ha scritto:
> Dear  Silvia
> About the material definition: I suppose you wish to have the equivallent
> of natural carbon, only with increased density. Then in the MATERIAL card,
> so not fill the fields relative to Am nad A: fill only the z and the name,
> the code will automatically consider the correct isotopic composition for
> Carbon.
> Then, you will have to add a LOW-MAT card in order to associate your new
> material with the low-energy neutron cross section data set (there is the
> example in the manual, in the description for LOW-MAT)
>  LOW-MAT      DIAMOND        6.       -2.      296.       0.0       0. CARBON
> About usrbin: the third quantity is the value that you plot, the fourth is
> the error in percentage
> The plotted value is energy/cm3/primary averaged over the third dimension
> You are asking for a bin size of 0.08 microns in z and 0.5 microns in x
> znd y. be aware that you are at the limit, or below, of the capabilitiees
> of the code, and IMPORTANT, that you will have toset very small values for
> the producton and transport thresholds in order to get something
> meaningful. Do you relly need such small bins?
> Also be aware that fluka will not deal with the crystal structure.
> Regards
> Paola
> > Dear experts,
> >
> > I'm a beginner with fluka. I have two questions:
> > - my target is made with diamond but I don't understand how set my
> > material
> > card in input. I wrote as All1 but it don't recognize this material.
> > - I don't understand what I obtain in a file ascii by setting userbin as
> > show you in All2. Because if I do a 2D plot in a file.dat i see 4 columns,
> > the first two are the two coordinates, the third and the fourth I don't
> > understand what show me.
> >
> > Thanks in advance.
> > Regards,
> >
> > Silvia
> >
> Paola Sala
> INFN Milano
> tel. Milano +39-0250317374
> tel. CERN   +41-227679148

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Received on Mon Feb 24 2020 - 16:05:50 CET

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