[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

[en] The X-radiation induced by ⁴He ion impact on Ag, Cd, In, Sn, Sb, Te and I has been investigated for incident energies ranging from 0.6 to 0.5 MeV. Production cross-sections for various X-ray lines have been obtained by an internal normalization method, by means of simultaneous backscattering measurements. From the intensities of the L_α, L_γ1,5 and L_γ2,3 lines the L-subshell ionization cross-sections have been extracted. Comparison with current theories shows systematic discrepancies for all the targets at incident energy below 2.0 MeV and, for Ag, Cd and In, even in the higher-energy region. These are attributed to deviations in the atomic parameters used in the data analysis as well as to a failure of the ionization theories employed

[en] K and L-shell x-ray production cross sections for Ag and I have been measured in the energy range 0.6 <= Esub(p) <= 3.8 MeV, using very thin targets. An ''internal'' method for evaluating the Si(Li) efficiency is outlined. The results are in good agreement with the usual theoretical approximations. (author)

[en] L x-ray production cross sections for ⁴He ion bombardment of Ag, Cd, In, Sn, Sb, Te and I have been measured in the energy range 0.6-5.0 MeV. Subshell ionisation cross sections have been extracted and compared with the predictions of the binary encounter approximation, the semiclassical approximation, and the perturbed stationary state theory. (author)

[en] L-shell X-ray production cross sections for selected heavy elements (Tl, Pb, Bi), of interest in BIO-PIXE analyses, have been measured by proton and ⁷Li ion impact in the energy range 0.8 - 2.6 MeV and 1.8 - 3.3 MeV respectively. Further, production cross sections for ⁷Li ion impact on Au between 1.0 and 2.4 MeV have been measured. L-subshell ionization cross sections have been extracted and arranged, together with similar results from other laboratories, in an analysis aiming at testing the performance of various theoretical approximations in the description of the ionization process. The disagreement observed at low values of the reduced velocity parameter ξ_L^R between the data and the predictions of the ECPSSR model is significantly reduced by using a United Atom approximation in the treatment of the binding correction, suggested by our group (ECPSSR-UA). The remaining discrepancies, mostly for the L₁-subshell, are almost completely removed by replacing the screened hydrogenlike wave functions with the more realistic Dirac-Hartree-Slater ones. In the case of ⁷Li ions, especially for L₂-subshell, also a more refined Coulomb deflection correction and more sophisticated coupled channel calculations are needed. (author)

[en] L x-ray production cross sections for ⁴He-ion bombardment of Pd and Cs have been measured in the energy range 0.6-5.0 MeV. An analysis, performed by including previous results, in the range of the atomic number Z 46≤Z≤ 55 confirms the linear dependence of the logarithm of the cross sections and the smooth dependence of the vacancy decay parameters around Z = 50 in relation to Z. The subshell ionisation cross sections have been compared with the predictions of the semiclassical approximation and of the perturbed stationary state theory taking into account energy loss, Coulomb retardation and relativistic effects (ECPSSR). The agreement with the ECPSSR calculations is generally good, except at the lowest incident energies. (author)

[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)

[en] L x-ray production cross sections for protons impinging on thin targets of Cd, Sb and Te have been measured in the energy range 0.3-2.0 MeV. L-subshell ionisation cross sections have been extracted and compared with existing data and with the predictions of the perturbed stationary-state theory including corrections for energy loss, Coulomb deflection, relativistic effects, binding energy and polarization. The results are in good agreement with analogous measurements on neighbouring elements and with results from other authors. A semiempirical value for the ω₁ fluorescence yield of Cd is suggested. (author)

[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] L X-ray line production cross sections for proton and ⁴He ion bombardment of elements with atomic number Z ranging from 59 to 70 have been measured in the energy range 0.25-1.80 MeV for protons and 0.40-1.80 meV for ⁴He ions. An overall good agreement with the few existing data has been observed. The linear dependence on Z of the logarithm of the cross sections has been confirmed also in this region. The agreement of the measured data with the predictions of a modified ECPSSR model, suggested by us and based on a recalculation of the binding correction (UA-ECPSSR), is generally good, except for the lowest incident energies. (Author)