Dear Fluka users,
I am using Fluka for simulations of activation in various particle
beams. At the moment, I am particularly interested in the activation of
air. I used 14 MeV proton, 28 MeV deuteron and 56 MeV alpha beams for my
simulations. While obtaining reasonable results for protons and alphas,
the result for deuterons was no activation at all. This result is in
contrast to my expectations and to cross section values given e.g. here:
http://www.oecd-nea.org/janisweb/
for e.g. deuteron induced reactions like N14 (d,n) O15, C12 (d,n) N13 or
O16 (d,n) F17 just to name a few. All these cross sections differ
significantly from zero for deuteron energies below 28 MeV.
I am not a long-term Fluka user and I was not able to find the mistake
in my input file, hence, I decided to ask this question to the mailing list.
To give a minimal example, I have simplified the geometry and setup to a
deuteron irradiation of Nitrogen in a 4 m cylindrical black hole
container. The four metre length should allow for all deuterons to be
stopped. From the cross sections I would at least expect the N14 (d,n)
O15 reaction to happen and produce a significant amount of F17.
What I get is a small amount of 11C with an uncertainty of 99% despite
40 cycles with 10^7 primaries. According to
http://www.oecd-nea.org/janisweb/ , N14 (d,n + alpha) C11 is a possible
reaction. However, the cross section is not significantly higher than
the well-documented N14 (d,n) O15 reaction which is not happening at all.
Additionally there are some N14 (n, something) something reactions
possible that do not seem to take place.
I expect some basic mistake in my input file that I fail to find myself.
I'd be grateful if someone would point me towards the origin of the
problem or maybe even present a solution. I'm appending my input and the
tab.lis file.
Thank you very much.
Best regards
Marius Arenz
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Received on Thu Oct 24 2019 - 16:14:19 CEST