The cross sections for the elastic scattering reactions 112,124 Sn(α,α) 112,124 Sn at energies above and below the Coulomb barrier are presented and compared to predictions for global α-nucleus potentials. The high precision of the new data allows a study of the global α-nucleus potentials at both the proton and neutron-rich sides of an isotopic chain. In addition, local α-nucleus potentials have been extracted for both nuclei, and used to reproduce elastic scattering data at higher energies. Predictions from the capture cross section of the reaction 112 Sn(α,γ) 116 Te at astrophysically relevant energies are presented and compared to experimental data.

Abstract. The transition between the Main Sequence and the Red Giant Branch in low mass stars is powered by the onset of CNO burning, whose bottleneck is 14 N(p, γ) 15 O. The LUNA collaboration has recently improved the low energy measurements of the cross section of this key reaction. We analyse the impact of the revised reaction rate on the estimate of the Globular Cluster ages, as derived from the turnoff luminosity. We found that the age of the oldest Globular Clusters should be increased by about 0.7−1 Gyr with respect to the current estimates.

Membrane separations are considered to be sustainable technologies because of their relatively low energy consumption. However, the fabrication of membranes is yet to turn green. Thin film composite (TFC) membranes...

The recent observation of a large electron screening effect in the d(d, p)t reaction using a deuterated Ta target has been confirmed using somewhat different experimental approaches: Ue = 309 ± 12 eV for the electron screening potential energy. The high Ue value arises from the environment of the deuterons in the Ta matrix, but a quantitative explanation is missing.

Context. The NO cycle takes place in the deepest layer of a H-burning core or shell, when the temperature exceeds T 30 × 10 6 K. The O depletion observed in some globular cluster giant stars, always associated with a Na enhancement, may be due to either a deep mixing during the red giant branch (RGB) phase of the star or to the pollution of the primordial gas by an early population of massive asymptotic giant branch (AGB) stars, whose chemical composition was modified by the hot bottom burning. In both cases, the NO cycle is responsible for the O depletion. Aims. The activation of this cycle depends on the rate of the 15 N(p, γ) 16 O reaction. A precise evaluation of this reaction rate at temperatures as low as experienced in H-burning zones in stellar interiors is mandatory to understand the observed O abundances. Methods. We present a new measurement of the 15 N(p, γ) 16 O reaction performed at LUNA covering for the first time the center of mass energy range 70−370 keV, which corresponds to stellar temperatures between 65 × 10 6 K and 780 × 10 6 K. This range includes the 15 N(p, γ) 16 O Gamow-peak energy of explosive H-burning taking place in the external layer of a nova and the one of the hot bottom burning (HBB) nucleosynthesis occurring in massive AGB stars. Results. With the present data, we are also able to confirm the result of the previous R-matrix extrapolation. In particular, in the temperature range of astrophysical interest, the new rate is about a factor of 2 smaller than reported in the widely adopted compilation of reaction rates (NACRE or CF88) and the uncertainty is now reduced down to the 10% level.