Two measurements of the Na-22+p resonant scattering via thicktarget inverse-kinematics method

Na-22 is an important isotope for the study of extinct radioactivity, meanwhile its sufficiently long half life provides the possibility to observe live Na-22 in nearby nova explosions. The Na-22(p,gamma)Mg-23 is one of the key reactions that influence the Na-22 abundance in nova ejecta. To study the proton resonant states in Mg-23 relevant to the astrophysical Na-22(p,gamma)Mg-23 reaction rates, two measurements have been carried out at the CRIB separator of University of Tokyo, and the RIBLL secondary beamline in Lanzhou, respectively. The Na-22 secondary beam was produced via the H-1(Ne-22,Na-22) n charge exchange reaction. Thick-target inverse-kinematics method is applied to obtain the excitation function of Na-22+ p elastic scattering. Extended gas target and solid state polyethylene foil were used in the two measurements, respectively, to map the different excitation energy region of the compound nucleus Mg-23. Several new resonant levels are observed and their contribution to the Na-22(p,gamma)Mg-23 reaction rate is evaluated.