Results 1 - 10 of 457
Results 1 - 10 of 457. Search took: 0.024 seconds
|Sort by: date | relevance|
[en] We observed single and double proton emissions in the 14O+4He interaction by the thick target inverse kinematic (TTIK) method at initial energy for 14O at 32.7 MeV. We found that the protons mainly originate from the resonance excitation of states in 18Ne. The observed states in 18Ne decay by protons mainly to proton unstable states in 17F. It was found that the decay of a state in 18Ne at Eex=8.45 MeV demonstrates the features of a decay by a correlated proton pair. The observed properties of the 14O+4He interaction make a previous interpretation for the rate of 14O(4He, p)17F at astrophysical energies suspect. We show how the TTIK method should be modified to obtain the data of astrophysical interest
[en] The half-life of the superallowed Fermi β emitter O was determined to high precision via a direct β counting experiment performed at the Isotope Separator and Accelerator (ISAC) facility at TRIUMF. The result, T(O) = 70619.2(76) ms, is consistent with, but is more precise than, the world average obtained from 11 previous measurements. Combining the O half-life deduced in the present work with the previous most precise measurements of this quantity leads to a reduction in the overall uncertainty, by nearly a factor of 2. The new world average is T(O) = 70619.6(63) ms with a reduced χ value of 0.87 obtained from 8 degrees of freedom.
[en] The 13N(d,n)14O reaction cross section has been measured using a high intensity 13N radioactive ion beam. This paper outlines the information which can be extracted from the knowledge of this stripping reaction and describes the specific detection set-up used for this experiment. (author)
[en] Single and double proton emissions in the 14O+4He interaction were observed with the thick target inverse kinematic method at initial energy for 14O at 32.7 MeV. It was found that the protons mainly originate from the resonance excitation of states in 18Ne. The decay of a state in 18Ne at Eex = 8.45 MeV demonstrates the features of a decay by a correlated proton pair
[en] A high-precision measurement of the 14O half-life has been performed using a mass-separated radioactive beam in combination with a germanium detector set-up. This is the first 14O half-life measurement with a contamination-free source. The final result of 70.560 ± 0.049 seconds is in agreement with the generally adopted mean value. (orig.)
[en] With using low-energy RI beams from an in-flight RIB separator, CRIB, the most crucial stellar reaction 14O(α,p)17F for the onset of the high-temperature rp-process was directly investigated and the transitions through the states at around 6.2 MeV in 18Ne were first observed, confirming the importance predicted before. The (α,p) reaction leading to the first excited state in 17F was also found to have a large contribution. A proton resonance search experiment of 23Mg + p was also discussed, which is a part of our series of resonance search studies relevant to the early stage of the rp-process
[en] The properties of the low lying states of 15F were studied by measuring the resonant elastic scattering of an 14O radioactive beam on protons. This experiment was performed at GANIL with a post-accelerated beam produced by the SPIRAL1 facility. We confirm the existence of a second excited state in 15F with a narrow width, which may seem particularly surprising for a state located above the Coulomb barrier.
[en] Coulomb excitation at intermediate energies is a useful tool in nuclear spectroscopy and nuclear astrophysics. Three examples of experiments with radioactive beams are mainly discussed: Coulomb excitation of 32Mg, Coulomb dissociation of 14O and 8B. (author)
[en] Experimental studies of nuclear astrophysics using intermediate-energy RI-beams are discussed. To overcome the low intensity and low emittance of the beams, we employed Coulomb dissociation and Coulomb excitation with reversed kinematics where the excitation energy is determined by measuring invariant masses or de-excitation γ energies. Various (p, γ) reactions in the pp chain, hot- and regular-CNO cycles and hot pp mode were investigated indirectly. (author)