Extended Optical Model Analyses of Elastic Scattering and Fusion Cross Sections for 6Li + 208Pb System at Near-Coulomb-Barrier Energies by using Folding Potential

Based on the extended optical model approach in which the polarization potential is decomposed into direct reaction (DR) and fusion parts, simultaneous $\chi^{2}$ analyses are performed for elastic scattering and fusion cross section data for the $^{6}$Li+$^{208}$Pb system at near-Coulomb-barrier energies. A folding potential is used as the bare potential. It is found that the real part of the resultant DR part of the polarization potential is repulsive, which is consistent with the results from the Continuum Discretized Coupled Channel (CDCC) calculations and the normalization factors needed for the folding potentials. Further, it is found that both DR and fusion parts of the polarization potential satisfy separately the dispersion relation.Comment: 6 figure

Fusion reaction of halo nuclei: A real-time wave-packet method for three-body tunneling dynamics

We investigate fusion cross section of a nucleus with a valence neutron, using the time-dependent wave-packet method. For a stable projectile, in which the valence neutron is tightly bound (e_n < -3 MeV), the neutron could enhance the fusion probability when the matching condition of orbital energies are satisfied. In contrast, for a halo nucleus, in which the binding energy of the neutron is very small (e_n>-1 MeV), the fusion probability is hindered by the presence of the weakly bound neutron.Comment: Talk at Internaitonal Conference on "Reaction Mechanisms and Nuclear Structure at the Coulomb Barrier" (FUSION06), Venice, Italy, March 19-23, 200

Extended Optical Model Analyses of Elastic Scattering, Direct Reaction, and Fusion Cross Sections for the 9Be + 208Pb System at Near-Coulomb-Barrier Energies

Based on the extended optical model approach in which the polarization potential is decomposed into direct reaction (DR) and fusion parts, simultaneous $\chi^{2}$ analyses are performed for elastic scattering, DR, and fusion cross section data for the $^{9}$Be+$^{208}$Pb system at near-Coulomb-barrier energies. Similar $\chi^{2}$ analyses are also performed by only taking into account the elastic scattering and fusion data as was previously done by the present authors, and the results are compared with those of the full analysis including the DR cross section data as well. We find that the analyses using only elastic scattering and fusion data can produce very consistent and reliable predictions of cross sections particularly when the DR cross section data are not complete. Discussions are also given on the results obtained from similar analyses made earlier for the $^{9}$Be+$^{209}$Bi system.Comment: 5 figure

Influence of severe thermal preconditioning on the bond between carbon FRCM and masonry substrate: Effect of textile pre-impregnation

Fabric-reinforced cementitious matrix (FRCM) composites often include polymer-impregnated bundles to improve the exploitation of the textile mechanical properties. However, organic components may degrade when exposed to elevated temperature. In this paper, the bond behavior of a carbon FRCM applied to a masonry substrate and exposed to a thermal preconditioning up to 300 °C for 250 min is investigated. Tensile tests on the textile and flexural and compression tests on the mortar matrix, as well as single-lap direct shear tests of FRCM-masonry joints with bare and impregnated textiles, are performed. Results show that the polymeric impregnation improves the mechanical properties of the FRCM even after thermal preconditioning

Simultaneous Optical Model Analyses of Elastic Scattering, Breakup, and Fusion Cross Section Data for the 6^{6}He + 209^{209}Bi System at Near-Coulomb-Barrier Energies

Based on an approach recently proposed by us, simultaneous $\chi^{2}$-analyses are performed for elastic scattering, direct reaction (DR) and fusion cross sections data for the $^{6}$He+$^{209}$Bi system at near-Coulomb-barrier energies to determine the parameters of the polarization potential consisting of DR and fusion parts. We show that the data are well reproduced by the resultant potential, which also satisfies the proper dispersion relation. A discussion is given of the nature of the threshold anomaly seen in the potential