Microscopic mechanism of the omega variation in moments of inertia for theseries of yrast SD bands Pb192-198(1) and Po-198(1)

The variations in moments of inertia (J((2)) and J((1))) with rotational fr equency for the series of yrast SD bands in even-even nuclei, (192-198) Pb( 1) and (198) Po(1), are investigated by using the particle-number conservin g method for treating the pairing interaction (monopole and quadrupole). Th e observed omega variations of J(2) and J(1) are reproduced quite well in t he PNC calculation, particularly the microscopic mechanism (the contributio ns from each major shell and each cranked Nilsson orbital) is clearly displ ayed. It is found that the smooth rise of J((2)) with omega is attributed t o the contribution from the intruder shells (neutron N = 7 and proton N=6).