No abstract

Populating states in22 Mg via the (p, t) reaction in inverse kinematics with a 55 MeV/nucleon 24 Mg beam, we have measured the proton-decay branching ratios of the levels at 5.96 MeV and 6.05 MeV and obtained an experimental upper limit on the branching ratio of the 5.71 MeV state. On the basis of the present and previous measurements, we assign spins and parities to the 5.96 MeV and 6.05 MeV states. We combine our branching ratios with independent measurements of the lifetimes of these states or their 22 Ne analogs to compute the resonance strengths and thereby the astrophysical rate of the 21 Na(p, γ) 22 Mg reaction. We perform hydrodynamic calculations of nova outbursts with this new rate and analyze its impact on 22 Na yields.

No abstract

No abstract

We have used photon emission spectroscopy to determine absolute, state-selective cross sections for single-electron capture by O 3+ ions colliding on atomic and molecular hydrogen. The impact energy was varied between 45 and 752 eV amu −1 . For O 3+ + H collisions we find that the cross section for capture into the 2p3s state of O 2+ strongly increases with impact energy up to an energy of ≈ 100 eV amu −1 . At higher impact energies the 2p3s cross section becomes comparable to the more or less constant 2p3p cross section. For the O 3+ + H 2 system these state-selective cross sections both stay approximately constant over the entire energy range investigated. Our results will be compared with existing experimental and theoretical data.