Level lifetimes in<i>N</i>=82 isotones from Doppler-shift attenuation method mixed-target measurements

Abstract

Lifetimes of the first excited states of the N=82 isotones $^{138}\mathrm{Ba}$, $^{140}\mathrm{Ce}$, and $^{142}\mathrm{Nd}$ have been measured simultaneously with the Doppler-shift attenuation method following inelastic neutron scattering and are found to be in excellent agreement with adopted literature values. In addition, lifetimes of excited states in heavier isotopes of neodymium have been determined. Of special interest are the E1 transitions for which transition strengths greater than ${10}^{\mathrm{\ensuremath{-}}3}$ W.u. are observed.