▪ Abstract This review summarizes current problems and questions in experimental nuclear astrophysics. It focuses on the present need for experimental data, emphasizing novel methods and approaches. Starting with an overview on nuclear energy generation and nucleosynthesis in an astrophysical plasma, the discussion concentrates on crucial problems related to the various aspects of stellar evolution, from the hydrostatic stage through the advanced burning scenarios up to and including the supernova explosion mechanism. Innovative experimental approaches are needed to pursue the associated questions in stellar nucleosynthesis. Particular emphasis is given to the potential use of radioactive ion beams and their importance for characterizing explosive nucleosynthesis in X-ray bursts and supernovae.

Current quests in nuclear astrophysics and experimental approaches

Nuclear astrophysics with radioactive beams

Absolute cross section of 7Be(p, γ)8B☆

▪ Abstract Radioactive nuclei play an important role in a diverse range of astrophysical phenomena including the early universe, the sun, red giant stars, nova explosions, X-ray bursts, supernova explosions, and supermassive stars. Measurements of reactions with beams of short-lived radioactive nuclei can, for the first time, probe the nuclear reactions occurring in these cosmic phenomena. This article describes the astrophysical motivation for experiments with radioactive beams, the techniques to produce these beams and perform astrophysically relevant measurements, results from recent experiments, and plans for future facilities.

Nuclear astrophysics measurements with radioactive beams

The quest to comprehend how nuclear processes influence astrophysical phenomena is driving experimental and theoretical research programs worldwide. One of the main goals in nuclear astrophysics is to understand how energy is generated in stars, how elements are synthesized in stellar events and what the nature of neutron stars is. New experimental capabilities, the availability of radioactive beams and increased computational power paired with new astronomical observations have advanced the present knowledge. This review summarizes the progress in the field of nuclear astrophysics with a focus on the role of indirect methods and reactions involving beams of rare isotopes.

Nuclear Astrophysics with Radioactive Beams

A recoil separator in combination with a windowless gas target has been designed for the measurement of the radiative capture reaction p(7Be, γ)8B. The separator consists of momentum and velocity filters and a ΔE−E detector telescope. The setup was tested quantitatively using the p(12C, γ)13N reaction at the effective energy Ecm = 841 keV. Projectile fluxes were measured directly with Faraday cups and indirectly with elastic backscattering into Si detectors, while the 13N recoil flux was measured directly with the ΔE−E telescope. A suppression of the 12C beam particles by a factor 2 × 10−10 was observed when the system was tuned for the recoil 13N's. Special emphasis was given to the charge state probabilities of the 13N recoils. Possible improvements of the system for the measurement of other capture reactions are discussed.

A recoil separator for the measurement of radiative capture reactions

The d(7Li,p)8Li Cross Section near Ecm = 0.61 MeV

The absolute cross section of the d(Li, p)Li reaction near the E "0.61 MeV resonance has been measured using a Li ion beam and a windowless gas target system filled with D gas. The proton yield of the reaction and the -delayed -activity of the residual nucl- ides Li were observed both concurrently with the elastic scattering yield, relating to the Rutherford scattering cross section . The resulting values, (from p)" 143.6$8.9 mb and (from Li)"151$20 mb, lead to a weighted mean value of "153$ 6m b ("2.26) including all available values and "146$ 5m b (" 0.05) removing some values from the data set. The conse- quences for the expected flux of high-energy solar neu- trinos are discussed.

M. Romoli

Papers

A recoil separator for the measurement of radiative capture reactions

The d(7Li,p)8Li Cross Section near Ecm = 0.61 MeV

The d(Li, p)Li cross section near Ecm"0.61 MeV