I have concentric sphere geometry to study the CR interaction . For reference, please look at the attached figure of the geometry.
Using SPECSOUR and GCR-SPE, I created a source at certain radius(indicated by the dotted line). Then, I set a USRBDX scoring between (REGION3,REGION2) and (REGION3, Outer blackbody). Region 3 is vaccum thus no interaction in that region. I am scoring the fluence in both cases. Also, I have taken into account the difference in the surface area in both cases. The 1D plot of both the USRBDX scoring is quite identical.
Does this mean that the particles from the generation sphere can have momentum either inward or outward? I am very new to fluka, so I want to understand these small setups before proceeding further.
Also, is there a way to dump the information of all the primary particles(coordinates, intial momentum direction, energy, etc) generated into a file(preferably csv or some file that can be analyzed in python).
Thanks a lot forwarding the link to the requisite material. I will have a look into it and get back with queries.
Please find attached the requisite input file. Isotropic.flair (4.0 KB)
The plot generated after applying the requisite normalisation is all follows. (Though I am not sure if I have mentioned the units of y-axis correctly. The y axis is multiplied by 50000 i.e - the total no of primaries )
The particle are injected from the spherical surface created on the base of the injection radius set in the SPECSOUR card. The fluence is inward only. However, particle are not injected in the radial (normal) direction only. So that, what you see in your results are particle emitted at different angles and that cross the entire geometry.
To cross check, you can increase the inner blackhole sphere and you will see the fluence gradually decrease.
Thanks a lot for the detailed expalination. I have tried to verify it with your suggested solution and it worked out perfectly.
I have a follow up question with the same input file. If you look at SPECSOUR card, the range of energy provided to sample from is 0.001 GeV to 500 GeV. But in the USRBDX plot, you can see there is non zero fluence beyond 500 GeV as well. Am I missing something obvious?
Once again, thanks a lot for reverting back to my queries.
Yes: the SPECSOUR interval refers to energy per nucleon [GeV/n] (actually per nuclear mass unit), while the USRBDX plot is obtained as a function of full particle energy [GeV], which makes a substantial difference for ions.