New Analysis of Levels in $^{151}$Pr

ORAL

Abstract

The previous reported levels and assignments to $^{151,152}$Pr [1,2] have recently been called into question [3] about the mass assignment of the reported bands [1,2]. 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. [4]. 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 $^{151}$Pr. In contrast to [3], the transitions previously assigned to $^{151}$Pr are all seen in the M-Z gated spectra. In addition, all the transitions in both bands previously assigned to $^{152}$Pr [2] are also seen in the $^{151}$Pr M-Z gated spectra but not in the $^{152}$Pr M-Z gated spectrum. Hence all four bands are now assigned to $^{151}$Pr. The new level scheme in $^{151}$Pr will be presented.\\[4pt] [1] J. K. Hwang \textit{et al.}, Phys. Rev. C~\textbf{82}, 034308 (2010).\\[0pt] [2] S. H. Liu \textit{et al.}, Phys. Rev. C~\textbf{84}, 044303 (2011).\\[0pt] [3] T. Malkiewicz \textit{et al.}, Phys. Rev. C~\textbf{85}, 044314 (2012). [4] A. Navin et al. (submitted); A. Navin, 5th Int. Conf. on~\textit{Fission and properties of neutron-rich nuclei, Sanibel 2012}, World Scientific, in press.

Authors

  • Enhong Wang

    • Vanderbilt University
  • J.H. Hamilton

    • Vanderbilt University
  • A.V. Ramayya

    • Vanderbilt University
  • J.K. Hwang

    • Vanderbilt University
  • A. Navin

    • GANIL
  • M. Rejmund

    • GANIL
  • A. Lemasson

    • GANIL
  • S. Bhattacharyya

    • GANIL
  • S.H. Liu

    • ORAU
  • N.T. Brewer

    • University of Tennessee
  • Y.X. Luo

    • LBNL
  • J.O. Rasmussen

    • LBNL
  • S.J. Zhu

    • Tsinghua University
  • G.M. Ter-Akopian

    • JINR
  • Yu. Oganessian

    • JINR