Investigation of binary processes in reactions 36Ar+144, 154Sm and 68Zn+112Sn leading to the formation of neutron-deficient 180, 190Hg composite systems.

Oct 16, 2020, 3:40 PM
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Oral report Section 2. Experimental and theoretical studies of nuclear reactions. Section 2. Experimental and theoretical studies of nuclear reactions

Speaker

Alexey Bogachev (JINR)

Description

Asymmetric fission process observed in decay of neutron-deficient nuclei lying in sub-lead (Pb) region provoked intensive investigations of fission process of these nuclei [1, 2]. Mass-energy and angular distributions of fission fragments of neutron-deficient 180, 190Hg composite systems formed in the reactions 36Ar + 144, 154Sm, 68Zn + 112Sn were measured using two-arm time-of-flight spectrometer CORSET [3] at energies near and above the Coulomb barrier. Analysis of the experimental data showed that in fission of these nuclei at the excitation energies up to 75 MeV both symmetric and asymmetric fission modes are clearly observed.
It was found that mass distributions of fragments formed in the reaction 68Zn + 112Sn have wide two humped shape with maximum yield at 70/110 amu for light and heavy fragments, respectively, and differ significantly from the distribution obtained in the reaction 36Ar + 144Sm leading to the formation of the same composite system of 180Hg. Difference of entrance channel properties in these two reactions leads to appearance of quasifission process in the reaction with 68Zn ions.
At highest incident energies fast fission process was observed [4] for composite systems of 180,190Hg. This occurs due to vanishing of fission barrier of formed composite system at large angular momenta. Fast fission process also widens the mass and energy distributions of fission fragments.
This work was supported by a joint grant program of the Indian Department of Science and Technology and the Russian Foundation for Basic Research, project no. 19-52-45023, as well as the Russian Science Foundation, project no. 19-42-02014.

[1] Itkis, M.G., Kondrat’ev, N.A., Mul’gin, S.I., et al.,Yad. Fiz., 1990, vol. 52, p. 944.
[2] Andreyev, A.N., Elseviers, J., Huyse, M., et al., Phys.Rev. Lett., 2010, vol. 105, 252502.
[3] Kozulin, E.M., Bogachev, A.A., Itkis, M.G., et al.,Instrum. Exp. Tech., 2008, vol. 51, p. 44.
[4] Ngo, C., Gregoire, C., Remaud, B., et al., Nucl. Phys. A,1983, vol. 400, p. 259.

Primary authors

Alexey Bogachev (JINR) Prof. Eduard Kozulin (FLNR) Dr Emanuele Vardaci (INFN-Na) Dr Wladislaw Trzaska (Department of Physics, University of Jyväskylä) Dr Galina Knyazheva (FLNR , JINR) Meghashree Cheralu House (Master's in Physics) Dr Iulia Itkis (FLNR, JINR) mikhail itkis (joint institute for nuclear research) Mr Kirill Novikov (FLNR, JINR) Mrs Nina Kozulina (Joint Institute for Nuclear Research (RU)) Dr Deepak Kumar (FLNR , JINR) I. N. Dyatlov (Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, Dubna, Russia) Mr Ivan Pchelintsev (FLNR,JINR) I. V. Vorob’ev (Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, Dubna, Russia) Dr Tathagatha Banerjee (FLNR,JINR) E. S. Mukhamedzhanov (Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, Dubna, Russia) A. N. Pan (Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, Dubna, Russia) Mr Alexandr Karpov V. V. Saiko (Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, Dubna, Russia) P. P. Singh (Faculty of Physics, Indian Institute of Technology—Ropar, Punjab, 140001 India) R. N. Sahu (Faculty of Physics, Indian Institute of Technology—Ropar, Punjab, 140001 India) Andreyev Andreev (University of York (GB)) Prof. Dan Mihai Filipescu (IFIN-HH, Bucharest ) M. Mayti (Faculty of Physics, Indian Institute of Technology Roorkee, Roorkee, 247667 India) R. Prajapat (Faculty of Physics, Indian Institute of Technology Roorkee, Roorkee, 247667 India) R. Kumar (Faculty of Physics, Indian Institute of Technology Roorkee, Roorkee, 247667 India)

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