Electromagnetic transition rates in 100,101Pd using the Recoil Doppler Shift Technique

The quadrupole deformations for the low-lying states in the transitional nuclei 100,101Pd100,101Pd have been deduced through the measurement of their electric quadrupole transition probabilities using the Recoil Distance Doppler Shift Method. The nuclei were studied using a 268 MeV 80Se beam impinging on a thin, self-supporting 24Mg target. States in 100Pd and 101Pd populated by the four and three neutron evaporation channels respectively, with reaction gamma-rays detected using the SPEEDY gamma-ray detection array. The recoiling nuclei were stopped in a copper foil and gamma-ray coincidence data taken at 10 separate target-stopper distances between 35μm and 750μm. The mean-lifetimes for the lowest lying 2+ (in 100Pd) and 15/2−15/2− (in 101Pd) states were measured to be 13.3(9) ps and 10.8(8) ps respectively. These data are compared with predictions from nuclear Total Routhian Surface calculations, which are found to agree with the experimentally deduced values to within 10%.

► The quadrupole deformations for the low-lying states in the transitional nuclei 100,101Pd have been deduced through the measurement of their electric quadrupole transition probabilities using the Recoil Distance Doppler Shift Method. ► The mean-lifetimes for the lowest lying 2+ (in 100Pd) and (15−/2)(15−/2) (in 101Pd) states were measured to be 13.3(9) ps and 10.8(8) ps respectively. ► The nuclear quadrupole deformations deduced from the measured transition rates are β2=0.143(5)β2=0.143(5) (2+ state in 100Pd) and β2=0.190(7)β2=0.190(7)(15−/2)(15−/2) state in 101Pd).