Re: dpdx=<0 problem in isotope user written source simulation

Your source routine is inputting MeV level energies as GeV (
18.1824493218291 MeV being read as 18.1824493218291 GeV) from the data
file. Of course this is assuming the kinetic energies sampled from the
source file are supposed to be in MeV....

Just modify the line:

TKEFLK (NPFLKA) = energy(sample)

to be

TKEFLK(NPFLKA) = energy(sample)/1000D0;

Once this was done, the simulation ran without any issue.

Also, I don't know if this part is deliberate, but your source routine
only reads 149 lines from the data file, but there's 200 lines in the file.

Hope this answers your question!

Cheers,

Nicholas Bolibruch

On 01/09/2010 9:08 PM, Ogawa Tatsuhiko wrote:
> Dear FLUKA experts,
>
> I am trying to transport isotopes using a user written source. But I
> don't know why it crashes saying
>
> Stepop, dp/dx=<0!! ij, z, a, mmat, ekin, pthrmx, dpdx0 -2 23 49 6 0.6
> 7.80517436 -543.194742
> Abort called from STEPOP reason dp/dx=<0 Run stopped!
> STOP dp/dx=<0
>
> in .err file.
>
> This happened regardless of WHAT(1) of BEAM card.
> It seems to have something to do with source energy because when I
> overwrite source kinetic energy (for example 18.1824493218291 -> 0.50),
> it runs.
>
> I would appreciate if someone could help me to run this simulation.
>
>
> Please find the attached files if necessary.
>
> coll.inp: input file
> source_frag.f: modified source.f file. Source file directory is defined
> in the 71st line.
> iso-source.dat: source information. the columns are atomic number, mass
> number, x,y,z coordinates, x,y,z angular cosines, kinetic energy (not
> divided by the number of nucleons), statistical weight, respectively
> from left to right.
>
> Many thanks in advance,
> Ogawa
>
>
Received on Mon Sep 06 2010 - 18:39:54 CEST