Gamma Decay of States ofY88Excited by theSr88(p,n)Y88Reaction

Abstract

The ${}_{}{}^{88}{}_{}{}^{}\mathrm{Sr}\mathrm{}(p,n)\mathrm{}{}_{}{}^{88}{}_{}{}^{}\mathrm{Y}$ and ${}_{}{}^{88}{}_{}{}^{}\mathrm{Sr}(p,n\gamma ){}_{}{}^{88}{}_{}{}^{}\mathrm{Y}$ reactions have been used to study the excited states of ${}_{}{}^{88}{}_{}{}^{}\mathrm{Y}$ up to an excitation energy of 1832 keV. Determinations of the excitation energies of 18 levels to an accuracy of ±1 and ±2 keV, for levels with excitation energies less than and greater than 800 keV, respectively, have been made. Angular distributions of five $\gamma$ rays deexciting states at 232, 393, 706, and 766 keV were measured and analyzed according to the statistical-model theory. This analysis confirms assignments of $J^{\pi }$ values of $5^{-}$, $1^{+}$, $2^{-}$, and $0^{+}$ to these respective states. Of particular interest is the $2^{-}$ level at 706 keV. The intensities of neutrons from the ${}_{}{}^{88}{}_{}{}^{}\mathrm{Sr}\mathrm{}(p,n)\mathrm{}{}_{}{}^{88}{}_{}{}^{}\mathrm{Y}$ reaction exciting levels up to 1832 keV have been compared with statistical-model calculations of the neutron yields to the respective states for particular assumed spin values. Consistent spin-parity assignments are given for many of the levels observed.