Spectroscopic Structure Of Exotic Na-19 - Astrophysics Implication

The structure of proton-rich isotope Na-19 was studied in resonance elastic scattering of a radioactive Ne-18 beam on a proton target using inverse-kinematics method [1]. Only one state of Na-19 (the second excited state) was observed. A combined R-matrix and potential model analysis was performed. The spin-parity assignment of the second excited state was confirmed to be 1/2(+). We kshow that the position of the 1/2(+) state significantly affects the astrophysicaly important Ne-18(2p,gamma) reaction rate through that state but the totalreaction rate remains unchanged 2p-capture on Ne-18 proceeds mostly via the ground and first excited states in Na-19 at stellar temperatures.