SATURATION OF B(E2) AND B(M1) STRENGTHS IN ACTINIDE NUCLEI

The saturation of the B(E2, 0(1)+ --> 2(1)+) strengths in the actinide nuclei is described very well by an analytical formula using shell closures at Z = 82, 126 and N = 126, 184. The transition towards saturation is much more gradual than in the rare-earth nuclei and reaches a saturation value of 325 +/- 10 W.u. By assuming a similar correlation between B(E2) and summed B(M1) strengths as observed in the rare-earth region we predict for actinide nuclei a saturation of the summed B(M1, 0(1)+ --> 1+) strengths below about 3 MeV of 3.7 +/- 0.4-mu-N2. We compare our estimates for (g-pi - g-nu)2 with values obtained from extrapolations of averaged regional boson g factors.