NUCLEAR-REACTIONS OF ASTROPHYSICAL INTEREST WITH RADIOACTIVE BEAMS

The ARENAS(3) facility, coupling the two cyclotrons of Louvain-la-Neuv e, is intensively been used over the past years for cross-section meas urements of nuclear reactions of astrophysical interest. We will descr ibe the characteristics of the available beams and the experiments goi ng on using these beams. The Ne-19(p,gamma)Na-20 reaction, of consider able importance for the reaction now between the CNO and the NeNa mass region in high-temperature hydrogen burning conditions, will be discu ssed in particular. The proposed low-energy resonance at 0.447 MeV has been measured in inverse kinematics using novel activation techniques . An upper limit (90% C.L.) of 18 meV is obtained for the strength of this first particle-unbound state of Na-20 together with preliminary v alues for the strength of the higher excited states.