cross sections of production: comparison with literature

From: <fiorini_at_lns.infn.it>
Date: Tue, 14 Jul 2009 15:49:29 +0200

Dear Fluka users,
I have some problems with the cross sections of production of some isotopes from
the reaction of a natural metal + protons. What I am trying to do is very
simple: I have a natural metal target and a proton beam, with different energy
for each input file from 1 to 30 MeV. From the reaction of target and beam,
several radioactive isotopes are produced. Counting the number of the photons of
decay, I can discover how many isotopes of the same kind are produced.
For example Fe + p produce, among others, Co56: counting how many photons at 846
or 1238 keV (created with different percentages by the decay of Co56) are
produced I can know how many Co56 are produced and so calculate the cross
section of production. The problem is that if I compare the cross sections
calculated using Fluka with this method and the cross sections of production of
Co56 (or Co57 counting the photons at 122 keV) in literature, the agreement is
not good, in particular at low proton energy.
I have noticed that the same happens for Cd and Cu targets.
In particular for the Cd target (thickness 0.1mm), I discovered that the cross
sections of production of In110 in ground state are completely different
compared to the cross sections in literature for proton energy lower than 30
MeV: the cross sections obtained with Fluka are larger. The same happens with In
110 (metastable state), but this time the cross sections produced with Fluka are
lower than those in literature. On the other hand, the cross sections of
production of In 110 (ground + metastable state) are quite comparable with those
in literature: the errors of the two separated isotopes combine to create
something comparable with the literature.
With Cu+p reactions, I went to look at the production of Zn63 and Zn65 (I used a
0.05mm thick target of copper). For Zn63 production the cross section becomes
comparable with those in literature from 14 MeV, and for Zn65 the cross section
is not comparable from around 12 to 20 MeV.

The number of photons is counted using the mgdraw routine combined with Paw to
visualise the data.
Do I have some problems in the input file or is the approach wrong?
Input file, the used routines and some graphs of the cross section comparison
are attached.

Thanks in advance
Francesca Fiorini

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Received on Tue Jul 14 2009 - 19:52:19 CEST

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