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The Trojan Horse Method (THM) has been applied extensively for the last 25 years to measure nuclear reaction cross sections of interest for astrophysics. Although it has been mainly applied for charged particle-induced reactions, recently it has been found to have also a relevant role for neutron-induced reactions. Here, some advantages of THM will be discussed and the preliminary results of the cosmological relevant 7Be(n,α)4He cross section measurement are discussed.

The fusion excitation function for the positive-Q-value system 12C+30Si (Qfus = +14.1 MeV) has been measured in inverse kinematics down to the μb level and compared with standard coupled-channel calculations. The appearance of the fusion hindrance phenomenon and the evidence of a S-factor maximum have been observed. This result can be significant to extrapolate the behavior of lighter astrophysical relevant systems at deep sub-barrier energies, where existing experimental data are still contradicting and affected by large errors.

One of the main ingredients of nuclear astrophysics is the knowledge of the thermonuclear reactions responsible for powering the stellar engine and for the synthesis of the chemical elements. At astrophysical energies the cross section of nuclear processes is extremely reduced by the effect of the Coulomb barrier and often extrapolations are needed. The Laboratory for Underground Nuclear Astrophysics (LUNA) is placed under the Gran Sasso mountain. Thanks to the environmental background reduction provided by its position many reactions involved in hydrogen burning has been measured directly at astrophysical energies. Based on this progress, currently there are efforts in several countries to construct new underground accelerators. The exciting science that can be probed with these new facilities will be highlighted.

Level widths in 15N have been measured with the nuclear resonance fluorescence (NRF) technique. Solid nitrogen compounds, bremsstrahlung, and HPGe detectors have been used as target, beam, and detectors, respectively. The preliminarily level widths are in agreement with the literature values, but more precise.

The detection of the 1809 keV emission line associated with the decay of 26Al in the interstellar medium provides a direct evidence of recent nucleosynthesis events in our galaxy. 26Al is thought to be mainly produced in massive stars, but in order to have a quantita- tive understanding of the 26Al distribution, the cross section of all the nuclear reactions involved in its production should be accurately known. A recent sensitivity study demonstrated that the 25Mg(α,n)28Si is the reaction with the strongest impact on the synthesis of 26Al during explosive Neon and Carbon burning [4]. In order to improve the experimental knowledge of the 25Mg(α,n)28Si cross section, a new direct measurement has been performed at Legnaro National Laboratories. The experimental setup, the data analysis and preliminary results are discussed.

The NeNa-MgAl cycles are involved in the synthesis of Ne, Na, Mg, and Al isotopes. The 20Ne(p,γ)21Na (Q = 2431.68 keV) reaction is the first and slowest reaction of the NeNa cycle and it controls the speed at which the entire cycle proceeds. At the state of the art, the uncertainty on the 20Ne(p,γ)21Na reaction rate affects the production of the elements in the NeNa cycle. In particular, in the temperature range from 0.1 GK to 1 GK, the rate is dominated by the 366 keV resonance corresponding to the excited state of EX = 2797.5 keV and by the direct capture component. The present study focus on the study of the 366 keV resonance and the direct capture below 400 keV. At LUNA (Laboratory for Underground Nuclear Astrophysics) the 20Ne(p,γ)21Na reaction has been measured using the intense proton beam delivered by the LUNA 400 kV accelerator and a windowless differential-pumping gas target. The products of the reaction are detected with two high-purity germanium detectors. The experimental details and preliminary results on the 366 keV resonance and on the direct capture component at very low energies will be shown, together with their possible impact on the 20Ne(p,γ)21Na reaction rate.

The 20Ne(p,γ)21Na is the first reaction of the NeNa cycle and having the slowest reaction rate, it controls the speed at which the entire cycle proceeds. This reaction is important in different stellar scenarios such as red giants stars (during H shell-burning), asymptotic giant branch stars, novae, and massive stars. Existing uncertainties on the 20Ne(p,γ)21Na are now the ones that severely affect the estimated elements production in the NeNa cycle. In particular, such uncertainties affect the amount of produced 22Na, a stellar γ-ray signature, and 22Ne, an important neutron source in the s-process, via the 22Ne(α,n)25Mg. Here, we propose to study the resonance at ER = 366 keV and to measure the 20Ne(p,γ)21Na reaction cross section at proton energies below 400 keV, in particular the contribution from the sub-threshold state, in order to better constrain the overall astrophysical rate of this important reaction. In this contribution, the experimental setup will be described and the expected results discussed.

Boron plays an important role in astrophysics and, together with lithium and beryllium, is a probe of stellar structure during the pre-main sequence and main-sequence phases. In this context, the 10B(p,α)7 Be reaction is of particular interest. The literature data show discrepancies in the energy range between 100 keV and 2 MeV. This also poses a normalization problem for indirect data obtained with the Trojan Horse Method. A new measurement of the 10B(p,α)7 Be reaction cross section was performed at Legnaro National Laboratories (LNL). At LNL, the cross section was determined with the activation technique by measuring the activated samples at a low-background counting facility. The analysis of that experiment is now complete and the results are here presented.