dear Paola,
Although the atomic mass of the ion indeed was part of the issue, it seems like there is more to it than that. After I have included amu, the result become aligned horizontally but not vertically (yes, I do multiply flux by amu).
The reason is possibly due to the way I calculate the normalization. I followed the Luigi's explanation here (under 5):
http://www.fluka.org/web_archive/earchive/new-fluka-discuss/8274.html
Specifically he says "For a discrete distribution, the normalisation is given by" the sum of fluxes at specific energy times the bin width. However, I realized that the fluka source files izphiMV.spc have different bin widths and therefore, since different bin widths matter, I can't use the equation that Luigi showed me.
Also, both izphiMV.spc files and the plot on page 2 of the fluka lecture are given as differential flux [#/cmq/s/sr/MeV] while the output of USRBDX is differential fluence [#/cmq/GeV/sr]. How and should I convert fluka result to the units of the plot?
thank you,
Roman
________________________________________
From: Paola Sala <paola.sala_at_mi.infn.it>
Sent: Tuesday, November 17, 2015 11:11 PM
To: Roman Savinov
Cc: fluka-discuss_at_fluka.org
Subject: Re: [fluka-discuss]: scoring specific particle of complex source
Dear Roman
your scoring is correct,
the difference is in the units:
The plot in page 2 of the fluka lecture gives particle spectra in MeV/amu,
that is energy per nucleon
USRBDX (and USRYIELD) outputs are in GeV, total energy
The difference in unit affects the horizontal scale and the normalization
by a factor (/ or *) atomic mass of the ion specie
Hope this helps
Paola
> dear Fluka experts,
>
>
> What is the proper way to score a specific particle (say He or C) from a
> composite source?
>
> I have GCR_IONF with WHAT(1)=6 meaning the source consist of H, He, ...,
> B, C. I am scoring with USRBDX. Hydrogen comes out right because there is
> a "proton" option in the drop down menu in USRBDX but what should I do to
> score, say, Helium or Carbon?
>
> I tried to use AUXSCORE by choosing Heavyion in USRBDX and Z=6 in
> AUXSCORE (or WHAT(2)=-600)
>
> The results doesn't match what I expect from here (pg.2):
>
> https://www.fluka.org/free_download/course/triumf2012/Lectures/AdvancedCosmicRays2012.pdf
>
> looks like Helium and Carbon spectras are shifted to the right and scaled
> down.
>
>
>
> <https://www.fluka.org/free_download/course/triumf2012/Lectures/AdvancedCosmicRays2012.pdf>thank
> you,
>
>
> Roman
>
>
>
>
Paola Sala
INFN Milano
tel. Milano +39-0250317374
tel. CERN +41-227679148
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Received on Fri Nov 20 2015 - 02:27:11 CET