Physics Letters B (Feb 2023)
Sequential fission and the influence of 208Pb closed shells on the dynamics of superheavy element synthesis reactions
- D.Y. Jeung,
- D.J. Hinde,
- M. Dasgupta,
- C. Simenel,
- E.C. Simpson,
- K.J. Cook,
- H.M. Albers,
- J. Buete,
- I.P. Carter,
- Ch.E. Düllmann,
- J. Khuyagbaatar,
- B. Kindler,
- N. Lobanov,
- B. Lommel,
- C. Mokry,
- E. Prasad,
- J. Runke,
- C. Sengupta,
- J.F. Smith,
- P. Thörle-Pospiech,
- N. Trautmann,
- K. Vo-Phuoc,
- J. Walshe,
- E. Williams,
- A. Yakushev
Affiliations
- D.Y. Jeung
- Department of Nuclear Physics and Accelerator Applications, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
- D.J. Hinde
- Department of Nuclear Physics and Accelerator Applications, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia; Corresponding author.
- M. Dasgupta
- Department of Nuclear Physics and Accelerator Applications, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
- C. Simenel
- Department of Nuclear Physics and Accelerator Applications, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia; Department of Fundamental and Theoretical Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
- E.C. Simpson
- Department of Nuclear Physics and Accelerator Applications, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
- K.J. Cook
- Department of Nuclear Physics and Accelerator Applications, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
- H.M. Albers
- SHE Chemistry Department, GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
- J. Buete
- Department of Nuclear Physics and Accelerator Applications, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
- I.P. Carter
- Department of Nuclear Physics and Accelerator Applications, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
- Ch.E. Düllmann
- SHE Chemistry Department, GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany; SHE Chemistry Section, Helmholtz Institute Mainz, 55099, Mainz, Germany; Department of Chemistry - TRIGA Site, Johannes Gutenberg-Universität Mainz, 55099, Mainz, Germany
- J. Khuyagbaatar
- SHE Chemistry Department, GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany; SHE Chemistry Section, Helmholtz Institute Mainz, 55099, Mainz, Germany
- B. Kindler
- Target Laboratory, GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
- N. Lobanov
- Department of Nuclear Physics and Accelerator Applications, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
- B. Lommel
- Target Laboratory, GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
- C. Mokry
- SHE Chemistry Section, Helmholtz Institute Mainz, 55099, Mainz, Germany; Department of Chemistry - TRIGA Site, Johannes Gutenberg-Universität Mainz, 55099, Mainz, Germany
- E. Prasad
- Department of Nuclear Physics and Accelerator Applications, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
- J. Runke
- SHE Chemistry Section, Helmholtz Institute Mainz, 55099, Mainz, Germany; Department of Chemistry - TRIGA Site, Johannes Gutenberg-Universität Mainz, 55099, Mainz, Germany
- C. Sengupta
- Department of Nuclear Physics and Accelerator Applications, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
- J.F. Smith
- Department of Nuclear Physics and Accelerator Applications, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
- P. Thörle-Pospiech
- SHE Chemistry Section, Helmholtz Institute Mainz, 55099, Mainz, Germany; Department of Chemistry - TRIGA Site, Johannes Gutenberg-Universität Mainz, 55099, Mainz, Germany
- N. Trautmann
- Department of Chemistry - TRIGA Site, Johannes Gutenberg-Universität Mainz, 55099, Mainz, Germany
- K. Vo-Phuoc
- Department of Nuclear Physics and Accelerator Applications, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
- J. Walshe
- Department of Nuclear Physics and Accelerator Applications, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
- E. Williams
- Department of Nuclear Physics and Accelerator Applications, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
- A. Yakushev
- SHE Chemistry Department, GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany; SHE Chemistry Section, Helmholtz Institute Mainz, 55099, Mainz, Germany
- Journal volume & issue
-
Vol. 837
p. 137641
Abstract
Measured binary quasifission mass spectra in reactions with actinide nuclides show a large peak in yield near the doubly-magic 208Pb. This has generally been attributed to the enhanced binding energy of 208Pb causing a valley in the potential energy surface, attracting quasifission trajectories. To investigate this interpretation, binary quasifission mass spectra and cross-sections have been measured at near-barrier energies for reactions of 50Ti with actinide nuclides from 238U to 249Cf. Cross-sections have also been deduced for sequential fission (a projectile-like nucleus and two fragments from fission of the complementary target-like nucleus). Binary cross-sections fall from ∼70% of calculated capture cross-sections for 238U to only ∼40% for 249Cf, with a compensating increase in sequential fission cross-sections. The data are consistent with the 208Pb peak originating largely from sequential fission of heavier fragments produced in more mass-asymmetric primary quasifission events. These are increasingly suppressed as the heavy quasifission fragment mass increases above 208Pb. The important role of sequential fission calls for re-interpretation of quasifission characteristics and dynamics in superheavy element synthesis reactions.
