[en] We report new experimental data concerning the elastic scattering of α-particles on ⁹Be nuclei in the bombarding energy region from 3.48 MeV up to 9.94 MeV, where a considerable lack of data exists in the literature. Data have been obtained at 110°, 135°, 150°, 160° backward polar angles suitable for IBA measurements. Excitation functions show various anomalies that can be linked to the presence of various excited states in the ¹³C compound nucleus. The present data have been compared with data reported in the literature, and an overall consistency is observed. The quality of the obtained excitation function at 160° has been benchmarked by performing EBS of α-particles on a thick and pure ⁹Be target at two bombarding energies

No abstract available

[en] Accurate studies on ¹³C spectroscopy have great impact in the present understanding of the role played by extra-neutrons in stabilizing α-cluster structures formed in light nuclei. Carbon-13 is in fact the simplest systems that can be formed by adding a neutron to make a triple-α molecular-like structure. The accurate spectroscopy of excited states at energies above the α emission threshold is fundamental to benchmark the calculations of theoretical models aiming to describe clustering in light nuclei.

To improve our knowledge of ¹³C structure, we performed a comprehensive R-matrix fit of α+⁹Be elastic and inelastic scattering data in the energy region E_α ≈ 3:510 MeV at several backward polar angles. To carefully determine the partial decay widths of states above the α-decay threshold we included in the fit also ⁹Be(α n)¹²C cross section data taken from the literature. This analysis allows to improve the (poorly known) spectroscopy of excited states in ¹³C in the E^x ≈ 12-17 MeV region, and tentatively suggests the presence of a large-deformation negative-parity molecular band. (paper)

No abstract available

[en] The study of the "1"9F(p,α)"1"6O reaction at low energy is important both for Nuclear Structure and Astrophysics. Despite of its importance, the S-factor of this reaction is poorly known, especially at astrophysical energies. We present an overview of the "1"9F(p,α_0)"1"6O reaction cross section, as obtained from recent direct measurements and from published works in the literature. We include in the systematic also data from an unpublished work, where several excitation functions and angular distributions for α_0 and α_π channels are reported. (paper)

[en] We discuss new results concerning the investigation of the "1"9F(p, α _0)"1"6O and "1"0B(p, α _0)"7Be reactions at low energies. Both reactions are important for the nuclear spectroscopy of the formed compound nucleus, i.e. "2"0Ne and "1"1C respectively, and play a role in nuclear astrophysics. For the "1"0B(p, α _0)"7Be case, a comprehensive analysis of our reaction data and other scattering data points out the possible presence of an unreported state in "1"1C at E_x ≈ 9.36 MeV. For the "1"9F(p, α _0)"1"6O case, the study of the low energy angular distributions testifies the role played by low energy resonances in the S-factor, leading to an enhanced reaction rate at stellar energies. (paper)

No abstract available

[en] We will discuss new experimental data concerning the elastic resonant scattering of α-particles on ⁹Be nuclei at bombarding energies from 3.5 MeV up to 9.9 MeV. Several excitation functions have been obtained at different polar angles, mainly in the backward hemisphere in the centre of mass frame. Excitation functions show various anomalies that can be linked to the presence of various excited states in the ¹³C compound nucleus. In the literature, some of these states have been proposed to belong to rotational bands built on deformed a-cluster excited state. Unfortunately, up to date the spin-parity assignment of many of these states is doubtful. The set of excitation functions we obtained from the present experiment can contribute to improve spectroscopy of highling excited states of ¹³C

[en] Isospin effects on dynamics of semi-central collisions involving ⁴⁰Ca + ⁴⁰Ca, ⁴⁰Ca + ⁴⁸Ca and ⁴⁸Ca + ⁴⁸Ca reactions at 25 MeV/nucleon have been investigated. For the selected class of events, the balance between the emission of evaporation residues and the presence of binary-like phenomena seems to be influenced by the neutron to proton ratio (N/Z) of entrance channels. In particular, for neutron-rich systems, evaporation residue emission is enhanced. Experimental observations confirm the key role played by the N/Z degree of freedom on nuclear dynamics at 25 MeV/nucleon. (authors)

[en] We discuss the preliminary results obtained by studying the α+⁹Be elastic scattering at bombarding energies from 3.5 to 10 MeV. Experimental spectra show the presence of elastic and inelastic scattering phenomena. Elastic scattering excitation functions have been obtained at various angles; their shape is in good agreement with data at backward angles reported in the literature.