Nuclear structure of 170Tm from neutron-capture and (d,p)-reaction measurements.

Abstract

We have made experimental measurements in $^{170}\mathrm{Tm}$ of the following: secondary \ensuremath{\gamma} rays, conversion electrons, and \ensuremath{\gamma}-\ensuremath{\gamma} coincidences from thermal neutron capture in $^{169}\mathrm{Tm}$, primary \ensuremath{\gamma} rays from average resonance capture with 2-keV and 24-keV neutron beams, and proton spectra from the (d,p) reaction on $^{169}\mathrm{Tm}$. From these data and those of previous investigations, we have identified more than 130 excited levels in $^{170}\mathrm{Tm}$ below 1550 keV. Of these, 62 (with connecting transitions) are placed in 18 rotational bands with assigned Nilsson configurations. These results are in good agreement with a semiempirical modeling of $^{170}\mathrm{Tm}$ level structure. Values for seven Gallagher-Moszkowski splittings and four Newby shifts have been obtained. These matrix elements show remarkably good agreement with calculation. Among the observed ${\mathit{K}}^{\mathrm{\ensuremath{\pi}}}$=${1}^{\mathrm{\ensuremath{-}}}$ and ${2}^{\mathrm{\ensuremath{-}}}$ rotational bands, configuration mixing appears to play a significant role. \textcopyright{} 1996 The American Physical Society.