The deformation of the neutron-rich isotopes¹⁰²Mo and¹⁰⁴Mo

Abstract

The half-lives of low-lying levels of the neutron-rich isotopes¹⁰²Mo and¹⁰⁴Mo have been measured at the fission product separator Josef with the ß-γ-γ triple coincidence technique. Values of t_1/2= 126(4)ps and 0.72(4)ns have been obtained for the 2₁ ⁺ levels at 296 keV and 192 keV in¹⁰²Mo and¹⁰⁴Mo, respectively. Deformation parameters of ß_q=0.28(1) and 0.31(1), respectively, are deduced, which are smaller than those of the isotones of Sr and Zr. The interacting boson model accounts well for the trend of 2⁺ energies in the Mo isotopes but slightly overpredicts the B(E2) values at saturation. A smooth dependence of τ 2₁ ⁺ vs. E 2₁ ⁺ is found for the A ∼ 100 region in agreement with the hydrodynamical model.