Experimental approach to explosive nucleosynthesis with RI beams

Abstract

Radio-isotope (RI) beams have opened up a new field in nuclear astrophysics in the last decade, especially for investigating explosive nucleosynthesis. Recent astronomical observations also have made a great advance that isotopic abundances rather than elemental abundances are obtained, which clearly indicate the stellar reactions responsible and also tells us exact amounts of radioisotopes synthesized in the stellar event. However, experimental studies of nuclear reactions of astrophysical interest with RI beams are usually quite difficult because of small beam intensities and small cross sections in many cases. New experimental methods have been developed to cope these difficulties in both direct and indirect methods. We will review recent experimental investigations for each nucleosynthesis scenario, which is based on the new experimental methods developed, such as the thick target method and the Asymptotic Normalization Coefficient Method (ANC) as well as the Coulomb dissociation method. The subjects here include nucleosynthetic problems from the primordial nucleosynthesis to the supernova nucleosynthesis. As for the study of the r-process, we discuss on the experiments performed with a heavy ion storage ring for precision mass and half-life measurement. A brief discussion is also made for the outlook of the field, especially possibilities at the up-coming RI beam facilities like the ones at RIBF at RIKEN and the ISOL-type RIB facility at TRIUMF.