New Levels in \textsuperscript{157}Pm
POSTER
Abstract
Gamma rays in coincidence with isotopically-identified fission fragments using VAMOS++ and EXOGAM, produced using \textsuperscript{238}U on a \textsuperscript{9}Be target, at an energy near the Coulomb barrier have been observed, as reported by Navin \emph{et al.}. In the present work, we have combined data from the in-beam mass- and Z-gated spectra with the $\gamma$-$\gamma$-$\gamma$-$\gamma$ data from \textsuperscript{252}Cf (SF) to assign transitions and levels in \textsuperscript{157}Pm. In contrast to Hwang (2009), the transitions previously assigned to \textsuperscript{156}Pm are all seen in the M-Z gated spectra of \textsuperscript{157}Pm and are not seen in the M-Z gated spectra of \textsuperscript{156}Pm. The new expanded levels of \textsuperscript{157}Pm are remarkably similar to those of the levels in \textsuperscript{155}Pm, which have been assigned as a well-deformed rotational band built on $\pi$ 5/2 [532], as in \textsuperscript{155}Pm. New level schemes in \textsuperscript{147}Ce are also verified and elaborated upon.
*Part of Vanderbilt University Physics \& Astronomy REU Program