Discovery of a new low energy neutron resonance of ${}^{89}$Y

A new neutron resonance of ${}^{89}$Y was discovered by time-of-flight (TOF) neutron capture experiments using a pulsed neutron beam from a spallation neutron source of the Japan Proton Accelerator Research Complex. The observed resonance energy was 19.7 eV that is much lower than the lowest energy (2.60 keV) of the previous reported resonances. In addition to the TOF measurement, nuclide identification of the resonance was made by prompt γ-ray analysis. Neutron capture γ-rays from ${}^{89}$Y were clearly observed only on the resonance. Resonance analysis was applied to the experimental results and the resonance parameters of the new resonance are given.