Zero scoring via USRBIN

Dear FLUKA experts,

I have been trying to score the ambient dose rate in regions (cubics) from a volumetric radioactive source (Be7) distributed over a watercourse. I have tried to maximize the size of the detectors (detect1 to detect7), increase the primaries number, and activate/deactivate AUXSCORE, but nothing worked, scoring zeros all the time. (see attached)

I would appreciate your advice.


Try.flair (4.9 KB)
Try.inp (4.3 KB)

Hello @yhusein,

I saw a first error in the definition of your detec regions. I let you see the differences but in a nutshell, you added -void in your detector regions definition instead of -det... in your VOID region.
Please have a look to the proposed modification and meanwhile I will investigate to solve your problem.

Try2.inp (4.3 KB)

1 Like

Dear @yhusein,

Mainly your problem was that the definition of your beam card was wrong. I modified it and now it’s corresponding to where is the water.
I tried with 1e8 primaries and I obtained a non-zero results.

Please let me know if it’s working now on your side.
In conclusion:

  • Be careful at the definition of your regions, you can use flair to check that your region definition is meaningful
  • an issue of the volumetric source definition

Try.flair (17.2 KB)
Try.inp (4.5 KB)

1 Like

Thank you very much for your help! I truly appreciate it.

However, I’m still a bit confused about your correction regarding the beam position card for volumetric sources, particularly in the context of FLUKA’s CART-VOL geometry.
In most FLUKA courses, it’s explained that the center of the volumetric source geometry is defined by the position specified in the beam position card. The lengths (x, y, and z) then represent the extent of the source in each direction, starting from this central point and reaching outwards.

Based on this understanding, I assumed that each length value (X, Y, and Z) represented half the total distance the source extends in that particular direction, measured from the center.
However, in your correction, you seemed to be referring to the entire side length. This doesn’t quite match the description I’ve encountered. Could you please clarify if I’m misunderstanding something?

Thanks again for your time and assistance.