New Analysis of Levels in $^{152}$Pr

ORAL

Abstract

The previous reported levels and assignments to $^{152}$Pr [1] have recently been called into question [2] about the mass assignment of the reported bands [1]. Recently prompt gamma-rays in coincidence with isotopically-identified fission fragments using VAMOS$++$ and EXOGAM, produced using $^{238}$U on a $^{9}$Be target, at an energy around the Coulomb barrier have been reported. [3]. We have combined the $\gamma -\gamma -\gamma -\gamma $ data from $^{252}$Cf (SF) and those from the in-beam mass- and Z-gated spectra to assign transitions and levels in $^{152}$Pr. The transitions previously assigned to $^{152}$Pr are all seen in the $^{151}$Pr M-Z gated spectra but not in the $^{152}$Pr M-Z gated spectrum. Hence the two bands are now assigned to $^{151}$Pr. Two new bands with 20 new transitions in $^{152}$Pr are identified from the $\gamma -\gamma -\gamma -\gamma $ coincidence and confirmed by the M-Z gated spectrum. The fission partners of Praseodymium (Yttrium isotopes) have a Gaussian yield distribution that peaks at 3n channel. The new level scheme of $^{152}$Pr will be presented. \\[4pt] [1] S. H. Liu et al., Phys. Rev. \textbf{C} 84, 044303 (2011). \\[0pt] [2] T. Malkiewicz et al., Phys. Rev. \textbf{C} 85, 044314 (2012). \\[0pt] [3] A. Navin et al. 5th Int. Conf. on ``Fission and properties of neutron-rich nuclei,'' World Scientific, in press.

Authors

  • E.H. Wang

    • Vanderbilt Univ.
  • J.H. Hamilton

    • Vanderbilt Univ.
  • A.V. Ramayya

    • Vanderbilt Univ.
  • J.K. Hwang

    • Vanderbilt Univ.
  • J.M. Eldridge

    • Vanderbilt Univ./Union Univ.
  • A. Navin

    • GANIL
  • M. Rejmund

    • GANIL
  • A. Lemasson

    • GANIL
  • S. Bhattacharyya

    • GANIL
  • S.H. Liu

    • Vanderbilt Univ./Univ. of Kentucky
  • N.T. Brewer

    • Vanderbilt Univ./Univ. of Tennessee, Knoxville
  • Y.X. Luo

    • Vanderbilt Univ.
  • J.O. Rasmussen

    • LBNL
  • S.J. Zhu

    • Tsinghua Univ.
  • G.M. Ter-Akopian

    • JINR(Dubna)
  • Yu. Ts. Oganessian

    • JINR(Dubna)