Studying astrophysical reactions with low-energy RI beams at CRIB

Studies on nuclear astrophysics, nuclear structure, and other interests have been performed using the radioactive-isotope (RI) beams at the low-energy RI beam separator CRIB, operated by Center for Nuclear Study (CNS), the University of Tokyo. A typical measurement performed at CRIB is the elastic resonant scattering with the inverse kinematics. One recent experiment was on the a resonant scattering with Li-7 and Be-7 beams. This study is related to the astrophysical Li-7/Be-7(alpha,gamma) reactions, important at hot p-p chain and vp-process in supernovae. There have also been measurements based on other experimental methods. The first THM measurement using an RI beam has been performed at CRIB, to study the F-18(p, alpha)O-15 reaction at astrophysical energies via the three body reaction H-2(F-18, alpha O-15)n. The F-18(p, alpha)O-15 reaction rate is crucial to understand the 511-keV gamma-ray production in nova explosion phenomena, and we successfully evaluated the reaction cross section at novae temperature and below experimentally for the first time.