Re: [fluka-discuss]: differential fluence distribution in SOURCE routine

From: Mikhail Polkovnikov <>
Date: Tue, 11 Aug 2015 19:24:37 +0300

On 11.08.2015 10:01, Roman Savinov wrote:
> Mikhail,
> I used files from your discussion with Faith:
> but instead of spectrum.dat I used different spectrum which I obtained
> by digitizing plot from this paper:
> (I have a fortran code that generates this data, srplot.f, but I don't
> know how to run it)
> The only thing I changed in your source_mod.f is I set NDIMMAX=58, the
> number of points in my spectrum.dat
> when I run it, all result points are zero. What might be the problem?
> Also, it seems like I have trouble with unit conversion with the
> results of my previous email. According to the
> test-3.sum.lis, USRTRACK gives results in protons/GeV/cm^2/primary
> I want result in protons/MeV/cm^2, just like in this paper (fig.5-8):
> so I need to convert 1/GeV to 1/MeV and multiply it by 5e5 primaries.
> To do the conversion I should _divide_ by 1000 but the fluka plot
> matches the plot of the source.dat only when I _multiply_ by 1000! WTF?
> Finally, what scoring cards should I use to make plots like fig.9-12
> of the "Shielding evaluation..." paper? Should I create detector at
> each point in depth of water slab where I want the dose to be probed
> or I can use one detector for the hole water slab and then do a 1-D
> projection to get a dose profile along the slab?
> thank you and sorry for the lengthy email
> Roman
Dear Roman,

1. To compile srplot.f you have to execute a commandgfortran srplot.f -o
srplot and to run it ./srplot.

2. In photon_spectrum archive what are dimensions of pairs in the file
If first column is an energy in GeV, than you should set photon energy

3. Where did you get 5e5 primaries? Is that a total fluence of yours? We
have differential point-wise fluence "dF/dE = C * exp(-(E - A) / B)",
where A, B, C - parameters and E - energy in MeV. Total fluence is an
integral from minimum to maximum energy "F = - C * B * exp( -(E - A) /
B) => Ftotal = F(Emax) - F(Emin) = F(2470) - F(0.1) = 1.84393E+10".

4. For scoring a dose try to use single USRBIN card with Type: x-y-z. If
your water slab along Z-axis, you can set NX = NY = 1. So your second
suggestion is correct.

Best regards,

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Received on Tue Aug 11 2015 - 20:08:29 CEST

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