CONVERGENCE OF THE MOMENTS OF INERTIA IN F-P-G SHELL NUCLEI

A survey of the kinematic moments of inertia of A almost-equal-to 80 nuclei shows a tendency to converge toward the rigid-body values of 20 to 25 HBAR2/MeV at rotational frequencies above 0.6 MeV/HBAR. The moments of the even-even isotopes approach the convergence zone from much lower values. The farther from the center of the shell, the lower the initial values axe and the more rapid is the rise. By contrast, the moments of inertia of the odd-odd nuclei start from higher values and decrease into the convergence zone. The values for odd-A nuclei are generally intermediate, usually starting somewhat below the final value and increasing into the 20 to 25 HBAR2/MeV region. The quadrupole deformations inferred from lifetimes in the even-even nuclei show no systematic change with spin, in contrast to the moments of inertia.