RE: spherical sources

From: Anton Lechner <>
Date: Mon, 10 Jun 2013 14:37:44 +0000

Dear Marzieh,

It is not possible to define multiple spherical sources within the same input file. However, there are two possible solutions to your problem:
*) The first possibility would be to run individual simulations for each of the four cases (i.e. each input file including different sphere center coordinates) and then just superimpose the results from each of the cases. This solution might be reasonable if the number of spheres is limited to a few (like in your case), however can easily become tedious if you are dealing with more sources.
*) The second solution would be to directly implement a customized position sampling of decaying isotopes in the source routine. In other words, you would need to replace in the routine following assignments with x,y,z positions sampled homogeneously over the spheres:

To your second question: you do not need to set SDUM of ASSIGNMA cards to VACUUM. This would only make sense if you would have radioactive decays in these regions and you would like that the decay products from these regions are ignored (e.g. if you would like to evaluate specifically the contribution from decays in other parts of the geometry).

Cheers, Anton

From: [] on behalf of Marzieh Anjomrouz []
Sent: 09 June 2013 08:32
To: fluka-discuss
Subject: spherical sources

Dear FLUKA Users

I want to define a source with 4 radioactive spheres filled by Palladium and placed in 4 positions as shown in the picture. So I defined a Beam card (ISOTOPE) along with a HI-PROBE (z=46,A=103).

Now my questions:

1) I know definition of spherical source (via 2 BEAMPOS, one for position of sphere and one for spherical shape) but I do not know how can I define 4 spherical sources located in 4 positions in one input file? Do I set 2 BEAMPOS cards for every source (8 BEAMPOS cards)? Do the FLUKA diagnose each spherical shape and followed position came after as a one source?

2) As seen in the picture, 2 internal spheres are not radioactive, so should I set MAT(decay) in the relevant ASSINMA card to vacuum to ignore decay interactions?


Received on Mon Jun 10 2013 - 17:38:54 CEST

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