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We report here a determination of the asymptotic normalization coefficient of the valence neutron in 8Li from a measurement of the angular distribution of the 7Li(8Li,7Li)8Li reaction at 11 MeV. Using isospin symmetry the 8B ANC has also been calculated and used to infer a value for S17(0) of 20.2 ± 4.4 eV b. [ABSTRACT FROM AUTHOR]

The 40Ca(α,γ)44Ti reaction is believed to be the main production channel for the radioactive nuclide 44Ti in core-collapse Supernovae. Radiation from decaying 44Ti has been observed so far for two supernova remnants, and precise knowledge of the 44Ti production rate may help improve supernova models. The 40Ca(α,γ)44Ti astrophysical reaction rate is determined by a number of narrow resonances. Here, the resonance triplet at Eα = 4497,4510, and 4523 keV is studied both by activation, using an underground laboratory for the γ counting, and by in-beam γ spectrometry. The target properties are determined by elastic recoil detection analysis and by nuclear reactions. The strengths of the three resonances are determined to be ωγ = (0.92 ± 0.20), (6.2 ± 0.5), and (1.32 ±0.24) eV, respectively, a factor of 2 more precise than before. The strengths of this resonance triplet may be used in future works as a point of reference. In addition, the present new data directly affect the astrophysical reaction rate at relatively high temperatures (above 3.5 GK). [ABSTRACT FROM AUTHOR]

Given the importance of Gamow-Teller (GT) transitions in nuclear structure and astrophysical nuclear processes, we have studied Tz = +3/2 → +1/2, GT transitions starting from the 47Ti nucleus in the (3He,t) charge-exchange reaction at 0° and at an intermediate incident energy of 140 MeV/nucleon. The experiments were carried out at the Research Center for Nuclear Physics (RCNP), Osaka, using the high-resolution facility with a high-dispersion beam line and the Grand-Raiden spectrometer. With an energy resolution of 20 keV, individual GT transitions were observed and GT strength was derived for each state populated up to an excitation energy (Ex) of 12.5 MeV. The GT strength was widely distributed from low excitation energy up to 12.5 MeV, where we had to stop the analysis because of the high level density. The distribution of the GT strengths was compared with the results of shell model calculations using the GXPF1 interaction. The calculations could reproduce the experimental GT distributions well. The GT transitions from the ground state of 47Ti and the M1 transitions from the isobaric analog state in 47V to the same low-lying states in 47V are analogous. It was found that the ratios of GT transition strengths to the ground state, the 0.088-MeV state, and the 0.146-MeV state are similar to the ratios of the strengths of the analogous M1 transitions from the isobaric analog state (IAS) to these states. The measured distribution of the GT strengths was also compared with those starting from the Tz = +3/2 nucleus 41K to the Tz = +1 /2 nucleus 41Ca. [ABSTRACT FROM AUTHOR]

The relatively short-lived radionuclide 44Ti is of considerable importance for the interpretation of nucleosynthesis in core-collapse supernova environments. Production is predominantly through the 40Ca(α,γ)44Ti reaction, which has been studied in this work over the energy range Ecm = 2.73--4.18 MeV, via direct γ counting and the 4π-summing technique, utilizing a previously characterized 12 inch × 12 inch single Nal crystal. The inferred reaction rate is compared here to both current experimental measurements and theoretical model calculations [ABSTRACT FROM AUTHOR]

The mass distributions of the fission fragments were measured in reactions induced by 48Ti beams on 144,154Sm, 162Dy, 174Yb, 186W, 192Os, ,196Pt, 200Hg, and 208Pb targets at near-barrier energies. The systematic tendencies of the mass widths have been explored. For the reactions with the lighter or spherical target nuclei, the mass widths increase with increasing bombarding energy, a behavior expected for fusion-fission. For the heavier and statically deformed nuclei, the mass widths increase rapidly as energies fall close to and below the capture barriers. Well above the barrier energies, the mass widths and estimated minimum quasifission contributions increase smoothly with increasing fissility of the composite nucleus. The observed behavior is a complex function of the rissility. deformation, and energy with respect to the capture barrier. Comparisons with dynamical quasifission model calculations for these reactions will be a good test of models of fusion in heavy-element formation reactions. [ABSTRACT FROM AUTHOR]