Quasifission Dynamics: Deformation and Orientation

ORAL

Abstract

Fusion reactions that lead to the formation of super-heavy compound nuclei are inhibited by competing processes such as quasifission, where the dinuclear system does not fully equilibrate and fuse to form a compound nucleus. For deformed nuclei, the orientation of colliding nuclei influences the probability of forming a compound nucleus. Axial/tip collisions have an empirical capture barrier [1][2][3] slightly below the average barrier due to decreased Coulomb repulsion from the formation of an elongated dinuclear system, but the elongated dinuclear system is less likely to equilibrate and form a compound nucleus, leading to increased quasifission outcomes. Equatorial/side collisions result in more compact shapes that are more likely to survive quasifission and form compound nuclei but have above average barriers due to increased Coulomb repulsion resulting from the more compact shape [1][2]. To further investigate the influence of orientation on quasifission and fusion-fission outcomes, we studied the reactions 32,36S + 232Th at a range of energies from 93% to 99% of the average barrier [4]. The total capture cross section will be extracted from measured fission cross sections [5] [6]. The ongoing analysis of 32S + 232Th will be discussed.

[1] K. Hammerton, et al., Physical Review C 99, 054621 (2019)

[2] D. J. Hinde, et al., PRL 74, 1295 (1995)

[3] D. Y. Jeung, et al., Physical Review C 103, 034603 (2021)

[4] D. J. Hinde, et al., PRL 101, 092701 (2008)

[5] R. du Rietz, et al., PRL 106, 052701 (2011)

[6] D. Y. Jeung. Ph.D. Thesis, The Australian National University (2018)

*This work is supported by the US Department of Energy office under DE-SC0021938 and DE-SC0022299. This material is also based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics and used resources of the Facility for Rare Isotope Beams (FRIB), which is a DOE Office of Science User Facility under Award Number DE-SC0000661.This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. 2235783

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Presenters

  • Caitlin E McCormick

    • Michigan State University/Facility for Rare Isotope Beams

Authors

  • Caitlin E McCormick

    • Michigan State University/Facility for Rare Isotope Beams

  • Kyle W Brown

    • Michigan State University/Facility for Rare Isotope Beams

  • Kaitlin J Cook

    • The Australian National University

  • David John Hinde

    • The Australian National University

  • Mahananda Dasgupta

    • The Australian National University

  • Jacob Buete

    • The Australian National University

  • Iulia M Harca

    • Facility for Rare Isotope Beams

  • Marshall J Basson

    • Michigan State University/Facility for Rare Isotope Beams