Dear FLUKA experts
I’m trying to re-produce this plot of 800 MeV protons interacting with a 5 cm radius infinite cylinder of Tungsten spallation experiment. The result should look like this:
However, the ouput I’m getting is this:
I’m using the ‘coalease’ card which is activated and ‘Evaporat’. Currently I’m using settings for Zmax = 0 and Amax = 0 as this provides the ‘WHAT 1’ card to be set to ‘3’ - which is ‘New Evap with Heavy Frag’.
However the material properties of tungesten is: Zmax = 74 and Amax = 184, when these are inputted the simulation crashes I get this error message below:
***** Z_max in PHYSICS/EVAPORAT not implemented *** *** Z_**
Can you please advise how to get the correct results please? I have also attached the input file here:
target_W_800MeV_p.inp (3.5 KB)
the tungsten numbers have nothing to do with the PHYSICS card enabling the emission of heavy fragments in the evaporation phase, where the Flair fields Amax and Zmax should be left empty, such as not to limit their available mass range.
You may have already obtained the correct results, as in your meaningful second plot, since it’s not clear what your expectations are based on. Your first plot seems to refer to other reaction simulation (rather than data) and the pronounced peak close to A=60 is hardly understandable at a first glance.
Thanks for the clarification.
I think the output should be based on residual fragments due to the nuclear reactions, the peak at around A = 60 I think refers to Iron, I’m not completly clear, however it be due to stability, which probably means this peak is needed. I’ve also attached the paper FYI - Although its very light on detail. You may find something that I missed!
spallation.pdf (180.1 KB)
Well, the paper contains indeed a quite crucial piece of info, namely the target composition adopted in the calculation, which was not pure tungsten, rather a mixture containing also nickel and iron, hence the resulting A~60 peak (that does not come from an unphysical special ‘stability’ of the residual fragment, rather from the additional presence of target isotopes of that mass, explaining the generation of close-by products). When implementing in FLUKA the reported target composition (by a dedicated COMPOUND MATERIAL), one retrieves the first plot.
Thanks - If I implement the compound material the graph should be reproduced? Is there a way of specifiying this in FLUKA?
MATERIAL 18.3 LATARG
COMPOUND -97.0 TUNGSTEN -2.1 NICKEL -0.9 IRONLATARG
ASSIGNMA LATARG r3TARG
Thanks for the clarification and advice.