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Indirect measurement of O-17(p,alpha)N-14 cross section at ultra-low energies
Sergi, M. L. ; Spitaleri, C. ; Coc, A. ; Mukhamedzhanov, A. ; Burjan, Václav ; Cherubini, S. ; Crucilla, V. ; Gulino, M. ; Hammache, F. ; Hons, Zdeněk ; Irgaziev, B. ; Kiss, G. G. ; Kroha, Václav ; La Cognata, M. ; Lamia, L. ; Pizzone, R. G. ; Puglia, S. M. R. ; Rapisarda, G. G. ; Romano, S. ; de Sereville, N. ; Somorjai, E. ; Tudisco, S. ; Tumino, A.
The indirect measurement of O-17(p,alpha)N-14 cross section was performed by means of the Trojan Horse Method. This approach allowed to investigate the ultra-low energy range (E-c.m.= 0-300 keV) relevant for several astrophysics environments, where two resonant levels of F-18 at E-c.m.(R) = 65 keV and E-c.m.(R) = 183 keV play a significant role in the reaction rate determination.
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Indirect Approach To The H-2(d,p)H-3 Reaction Study
Sparta, R. ; Pizzone, R. G. ; Spitaleri, C. ; Aliotta, M. ; Burjan, Václav ; Cherubini, S. ; Crucilla, V. ; Gulino, M. ; Hons, Zdeněk ; Kiss, G. G. ; Kroha, Václav ; La Cognata, M. ; Lamia, L. ; McCleskey, M. ; Mrázek, Jaromír ; Puglia, S. M. R. ; Rapisarda, G. G. ; Romano, S. ; Sergi, M. L. ; Trache, L. ; Tumino, A.
In order to understand primordial and stellar nucleosynthesis, we have studied H-2(d,p)H-3 reaction at 0.4 MeV down to astrophysical energies. Knowledge of its S-factor is interesting also to plan reactions for fusion reactors to produce energy. The H-2(d,p)H-3 reaction has been studied through the Trojan Horse Method applied to the three-body reaction H-2(He-3,pt)H, at beam energy of 17 MeV. Once selection of protons and tritons detected in coincidence and the selection of quasi-free events, the obtained S-factor is compared with direct measurements. Such data are in agreement with the direct ones and a pole invariance test has been obtained comparing the present results with another H-2(d,p)H-3 THM measurements, where a different spectator particle was employed.
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Spectator invariance test in the study of the Li-6,Li-7 fusion reactions via the Trojan Horse Method
Pizzone, R. G. ; Lamia, L. ; Bertulani, C. A. ; Mukhamedzhanov, A. ; Spitaleri, C. ; Blokhinstev, L. ; Burjan, Václav ; Cherubini, S. ; Hons, Zdeněk ; Kiss, G. G. ; Kroha, Václav ; La Cognata, M. ; Li, C. ; Mrázek, Jaromír ; Piskoř, Štěpán ; Puglia, S. M. R. ; Rapisarda, G. G. ; Romano, S. ; Sergi, M. L. ; Tumino, A.
Fusion reactions play a crucial role for several astrophysical scenarios. At the low energies typical of such environments direct measurements of reaction cross sections are very difficult, and even sometimes impossible. In such cases the use of indirect methods can give a substantial help. The Trojan Horse Method (THM) is based on the quasi-free break-up of a nucleus, which can be described in terms of a cluster structure. In such applications the independence of THM results with different break-up schemes, was tested using the quasi free(3)He(Li-6,alpha alpha)H and He-3(Li-7,alpha alpha)H-2 reactions. Results were then compared with the direct behaviours obtained from available data as well as with the cross sections extracted from previous indirect investigations of the same binary reactions using a different nuclide as a Trojan Horse nucleus.
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Features of Nuclear Reactions with Light Weakly Bond Nuclei at Energy near the Coulomb Barrier
Skobelev, N. K. ; Penionzhkevich, Y. E. ; Kroha, Václav ; Burjan, Václav ; Hons, Zdeněk ; Mrázek, Jaromír ; Piskoř, Štěpán ; Šimečková, Eva ; Voskoboynik, E. I.
In the experiments carried out by ion beam He-6 of the cyclotron complex DRIBs (JINR) and He-3 beam cyclotron U-120M of the NPI, Czech Academy of Sciences have been investigated reaction Sc-45+He-3, He-6 and Au-197+He-3, He-6 in the energy range near the Coulomb barrier. It were obtained the experimental values of the cross sections for complete fusion reactions and direct reactions for formation of the isotopes Sc-43, Sc-44 and Sc-46 also Au-196 and Au-198 as a function of the bombarding He-3 and He-6 energy. Despite the low binding energy of He-3 and the positive Q-values leading to the formation of isotopes Sc-44 and Sc-46 also Au-196 and Au-198, the behavior of the excitation functions with the formation of these isotopes is different from the excitation functions for d, He-6.
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