29 research outputs found

    The origin of correlation between mass and angle in quasi-fission

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    Mass-angle distribution (MAD) measurement of heavy and superheavy element fragmentation reactions is one of the powerful tools for investigating the mechanism of fission and fusion process. MAD shows a strong correlation between mass and angle when the quasi-fission event is dominant. It has characteristic that appears diagonal correlation as long as the quasi-fission event is dominant. This diagonal correlation could not be reproduced in previous our model before the introduction of the parameters. In this study, we systematically evaluate the unknown model parameters contained in our model and clarify those model parameters to reproduce the diagonal correlation that appears in MAD. Using a dynamical model based on the fluctuation dissipation theorem that employs Langevin equations, we calculate MADs of two reaction systems 48^{48}Ti+186^{186}W and 34^{34}S+232^{232}Th which are dominated by quasi-fission. We were able to clarify the effects of unknown model parameters on the MAD. In addition, we identified the values of model parameters that can reproduce the correlation between mass and angle. As a result, it was found that the balance of tangential friction and moment of inertia values is important for the correlation between mass and angle.Comment: 5 pages, 2 figures, SND2020. arXiv admin note: text overlap with arXiv:2309.11095, arXiv:2310.02547, arXiv:2310.0721

    Measurement of fission-fragment mass distributions in the multinucleon transfer channels of the 18O+237Np^18O+^237Np reaction

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    International audienceFission-fragment mass distributions for 23 nuclei (U234−237, Np236−239, Pu238−241, Am240−243, Cm242−245, and Bk244−246) were measured using the multinucleon transfer approach in the reaction of O18+Np237, and their excitation-energy dependence was obtained up to a maximum of 70 MeV. Among them, the low-energy fission of Np236, Pu238, and Cm245 is reported for the first time. The experimental data for all the studied nuclei were compared to the Langevin calculations. The calculation which takes into account the effects of multichance fission well reproduced the peak-to-valley ratio and mass-asymmetric peak positions of the distributions. The angular momentum given to the fissioning nucleus is also discussed

    Investigation into the supramolecular properties of fibres regenerated from cotton based waste garments

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    This paper investigated the supramolecular properties and accessibility of fibres regenerated from cotton-based waste garments and compared to typical lyocell fibres. The supramolecular and accessibility properties of the cotton-based waste garments fibres regenerated from three sources (waste denim garments, easy care finished cotton fabrics and a blend of cotton-based waste garment with wood pulp) were analyzed and compared to the lyocell fibres. The Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy and Wide Angle X-ray Diffraction (WAXD) analyses indicated that the fibres from cotton waste garments had supramolecular properties similar to the typical lyocell fibres. The exception was spun from the cotton pulp reclaimed from easy care treated cotton fabrics and maybe related to increased amorphous cellulose content in its structure. The fibre’s accessibility by reagents behaviour correlated well with the supramolecular properties. The results indicate that the waste garment purification process may affect the properties of the pulp and hence the supramolecular properties of the resultant fibres. Further research on the purification and regeneration of fibres from waste garments may lead to the use of cotton waste garments as an alternative feedstock source to the lyocell process
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