## 5 Results: Mass, Charge, and Energy Distributions of Secondary Particles
The energy peak at around the beam energy shows up at the highest energies being the consequence of the smaller wavelength and higher transparency of the nucleus to the incoming protons and the opening of the p-p and p-n direct inelastic interactions. A further feature common at all energies is the copious production of neutrons. This is because merely all nuclear collisions (except elastic) that are involved produce neutrons. Being neutrons more penetrating than charged radiations, their contribution to the dose absorbed by the astronauts can be relatively very large. Therefore, the capability of the shielding material to reduce the escape of neutrons is a challenge for the development of any shielding material. The overall picture coming from the mass, charge, and energy distributions of the secondary products is therefore consistent with expectations of the general trend of nuclear reaction mechanisms with the bombarding energy. It is important to remark that, as a second step, the code DOSE takes care of the transport of these secondary particles in the medium. In principle, such particles, besides being slowed down by electromagnetic interactions, may interact again with the nuclei in the medium and give rise to hadronic processes (capture, inelastic processes, evaporation) of the same type of the one already discussed. Therefore, the check on the reliability of the implementation of those processes that forge secondary particles gives confidence that the transport of secondary radiation is also performed in a reliable manner. Figure 4: Computed atomic and mass numbers (Z, A) of the secondary particles produced as a result of the proton\(\rightarrow\)Nomex interaction for different energy values that characterize the spectrum of GCRs. (**a**) 50 MeV, (**b**) 100 MeV, (**c**) 200 MeV, (**d**) 500 MeV, (**e**) 800 MeV, (**f**) \(\sim\)1000 MeV. secondary radiation in the target from the point of view of the implemented processes. We remarked the production of ions of masses and charges lower than the original chemical elements, but also a consistent production of neutrons, protons, and alpha particles. As secondary radiation can escape the shield and possibly be more harmful than the incoming radiation (for instance, neutrons because of their higher penetrability), it is necessary to consider the transport of this secondary radiation in the same shielding material and to evaluate the dose absorbed as a function of the distance from the shield. This part of the work will be the subject of an article in preparation. Conceptualization, F.L., E.V. and M.Q. ; methodology, F.L., E.V. and M.Q. ; software, F.L. and D.B. ; validation, F.L., E.V. and M.Q. ; formal analysis, F.L., D.B., A.D.N. ; investigation, F.L., and E.V. ; resources, F.L. and M.Q. ; data curation, F.L., E.V. and M.Q. ; writing--original draft preparation, F.L., E.V. and M.Q. ; writing--review and editing, F.L., E.V., D.B., A.D.N. and M.Q. ; visualization, F.L., E.V., D.B., A.D.N. and M.Q. ; supervision, F.L. and E.V. ; project administration, F.L., E.V. and M.Q  
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