1,154 research outputs found

    The Onset of Nuclear Structure Effects in Near-Barrier Elastic Scattering of Weakly-Bound Nuclei: 6^6He and 6^6Li Compared

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    The elastic scattering of the halo nucleus 6^6He from heavy targets at incident energies near the Coulomb barrier displays a marked deviation from the standard Fresnel-type diffraction behavior. This deviation is due to the strong Coulomb dipole breakup coupling produced by the Coulomb field of the heavy target, a specific feature of the nuclear structure of 6^6He. We have performed Continuum Discretized Coupled Channels calculations for the elastic scattering of 6^{6}He and 6^6Li from 58^{58}Ni, 120^{120}Sn, 144^{144}Sm, 181^{181}Ta and 208^{208}Pb targets in order to determine the range of ZTZ_{\mathrm T} where this nuclear-structure specific coupling effect becomes manifest. We find that the strong Coulomb dipole breakup coupling effect is only clearly experimentally distinguishable for targets of ZT80Z_{\mathrm T} \approx 80.Comment: 10 pages with 3 figure

    Failure of the Standard Coupled-Channels Method in Describing the Inelastic Reaction Data: On the Use of a New Shape for the Coupling Potential

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    We present the failure of the standard coupled-channels method in explaining the inelastic scattering together with other observables such as elastic scattering, excitation function and fusion data. We use both microscopic double-folding and phenomenological deep potentials with shallow imaginary components. We argue that the solution of the problems for the inelastic scattering data is not related to the central nuclear potential, but to the coupling potential between excited states. We present that these problems can be addressed in a systematic way by using a different shape for the coupling potential instead of the usual one based on Taylor expansion.Comment: 10 pages, 4 figures, 1 table, Latex:RevTex4 published in J. Phys. G: Nucl. Part. Phy

    Global Examination of the 12^{12}C+12^{12}C Reaction Data at Low and Intermediate Energies

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    We examine the 12^{12}C+12^{12}C elastic scattering over a wide energy range from 32.0 to 70.7 MeV in the laboratory system within the framework of the Optical model and the Coupled-Channels formalism. The 12^{12}C+12^{12}C system has been extensively studied within and over this energy range in the past. These efforts have been futile in determining the shape of the nuclear potential in the low energy region and in describing the individual angular distributions, single-angle 500^{0} to 900^{0} excitation functions and reaction cross-section data simultaneously. In order to address these problems systematically, we propose a potential that belongs to a family other than the one used to describe higher energy experimental data and show that it is possible to use it over this wide energy range. This potential also predicts the resonances at correct energies with reasonable widths.Comment: 30 pages with 13 eps figues and 3 tables, LaTeX-Revtex

    Drying kinetic analysis of municipal solid waste using modified page model and pattern search method

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    This work studied the drying kinetics of the organic fractions of municipal solid waste (MSW) samples with different initial moisture contents and presented a new method for determination of drying kinetic parameters. A series of drying experiments at different temperatures were performed by using a thermogravimetric technique. Based on the modified Page drying model and the general pattern search method, a new drying kinetic method was developed using multiple isothermal drying curves simultaneously. The new method fitted the experimental data more accurately than the traditional method. Drying kinetic behaviors under extrapolated conditions were also predicted and validated. The new method indicated that the drying activation energies for the samples with initial moisture contents of 31.1 and 17.2 % on wet basis were 25.97 and 24.73 kJ mol−1. These results are useful for drying process simulation and industrial dryer design. This new method can be also applied to determine the drying parameters of other materials with high reliability
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