Background: Observation of asymmetric fission of Hg180 has led to intensive theoretical and experimental studies of fission of neutron-deficient nuclei in the lead region. Purpose: The study of asymmetric and symmetric fission modes of Hg180,190 and Pb184,192,202 nuclei. Methods: Mass-energy distributions of fission fragments of Hg180,190 and Pb184 formed in the Ar36+Sm144,154 and Ca40+Sm144 reactions, respectively, at energies near the Coulomb barrier have been measured using the double-arm time-of-flight spectrometer CORSET and compared with previously measured Pb192,202 isotopes produced in the Ca48+Sm144,154 reactions. The mass distributions for Hg180,190 and Pb184,192,202 together with old data for Ir187, Au195, Hg198, Tl201, Bi205,207, Po210, and At213 [J. Nucl. Phys. 53, 1225 (1991)] have been decomposed into symmetric and asymmetric fission modes. The total kinetic-energy distributions for different fission fragment mass regions have been analyzed for Hg180,190 and Pb184. Results: The stabilization role of proton numbers at Z≈36, 38, Z≈45, 46, and Z=28/50 in asymmetric fission of excited preactinide nuclei has been observed. The high (≈145-MeV) and the low (≈128-MeV) energy components have been found in the total kinetic-energy distributions of Hg180,190 fission fragments corresponding to the fragments with proton numbers near Z≈46 and Z≈36, respectively. In the case of fission of Pb184 only the low-energy component (≈135MeV) for the fragments with masses corresponding to the proton numbers Z≈36 and 46 has been found. Conclusions: The studied properties of asymmetric fission of Hg180,190 and Pb184,192,202 nuclei point out the existence of well deformed proton shell at Z≈36 and less deformed proton shell at Z≈46.

Asymmetric and symmetric fission of excited nuclei of Hg 180,190 and Pb 184,192,202 formed in the reactions with Ar 36 and Ca 40,48 ions / Bogachev, A. A.; Kozulin, E. M.; Knyazheva, G. N.; Itkis, I. M.; Itkis, M. G.; Novikov, K. V.; Kumar, D.; Banerjee, T.; Diatlov, I. N.; Cheralu, M.; Kirakosyan, V. V.; Mukhamejanov, Y. S.; Pan, A. N.; Pchelintsev, I. V.; Tikhomirov, R. S.; Vorobiev, I. V.; Maiti, M.; Prajapat, R.; Kumar, R.; Sarkar, G.; Trzaska, W. H.; Andreyev, A. N.; Harca, I. M.; Vardaci, E.. - In: PHYSICAL REVIEW C. - ISSN 2469-9985. - 104:2(2021). [10.1103/PhysRevC.104.024623]

Asymmetric and symmetric fission of excited nuclei of Hg 180,190 and Pb 184,192,202 formed in the reactions with Ar 36 and Ca 40,48 ions

Vardaci E.
2021

Abstract

Background: Observation of asymmetric fission of Hg180 has led to intensive theoretical and experimental studies of fission of neutron-deficient nuclei in the lead region. Purpose: The study of asymmetric and symmetric fission modes of Hg180,190 and Pb184,192,202 nuclei. Methods: Mass-energy distributions of fission fragments of Hg180,190 and Pb184 formed in the Ar36+Sm144,154 and Ca40+Sm144 reactions, respectively, at energies near the Coulomb barrier have been measured using the double-arm time-of-flight spectrometer CORSET and compared with previously measured Pb192,202 isotopes produced in the Ca48+Sm144,154 reactions. The mass distributions for Hg180,190 and Pb184,192,202 together with old data for Ir187, Au195, Hg198, Tl201, Bi205,207, Po210, and At213 [J. Nucl. Phys. 53, 1225 (1991)] have been decomposed into symmetric and asymmetric fission modes. The total kinetic-energy distributions for different fission fragment mass regions have been analyzed for Hg180,190 and Pb184. Results: The stabilization role of proton numbers at Z≈36, 38, Z≈45, 46, and Z=28/50 in asymmetric fission of excited preactinide nuclei has been observed. The high (≈145-MeV) and the low (≈128-MeV) energy components have been found in the total kinetic-energy distributions of Hg180,190 fission fragments corresponding to the fragments with proton numbers near Z≈46 and Z≈36, respectively. In the case of fission of Pb184 only the low-energy component (≈135MeV) for the fragments with masses corresponding to the proton numbers Z≈36 and 46 has been found. Conclusions: The studied properties of asymmetric fission of Hg180,190 and Pb184,192,202 nuclei point out the existence of well deformed proton shell at Z≈36 and less deformed proton shell at Z≈46.
2021
Asymmetric and symmetric fission of excited nuclei of Hg 180,190 and Pb 184,192,202 formed in the reactions with Ar 36 and Ca 40,48 ions / Bogachev, A. A.; Kozulin, E. M.; Knyazheva, G. N.; Itkis, I. M.; Itkis, M. G.; Novikov, K. V.; Kumar, D.; Banerjee, T.; Diatlov, I. N.; Cheralu, M.; Kirakosyan, V. V.; Mukhamejanov, Y. S.; Pan, A. N.; Pchelintsev, I. V.; Tikhomirov, R. S.; Vorobiev, I. V.; Maiti, M.; Prajapat, R.; Kumar, R.; Sarkar, G.; Trzaska, W. H.; Andreyev, A. N.; Harca, I. M.; Vardaci, E.. - In: PHYSICAL REVIEW C. - ISSN 2469-9985. - 104:2(2021). [10.1103/PhysRevC.104.024623]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11588/861126
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