LIFETIME MEASUREMENTS OF THE HIGH-SPIN YRAST STATES IN CE-128

Lifetime measurements of the high spin states in the yrast band of Ce- 128 were performed using the Doppler shift attenuation method in conne ction with the reaction Ru-100(S-32, 2p2n) Ce-128 at incident energy o f 141 MeV. In the vicinity of the band crossing, the previously report ed anomalously high B(E2) value was not observed. The gross behavior o f the normalized transition strength is approximate to symmetric rotor . It is confirmed that the trend of increase in collectivity with decr easing neutron number, which was indicated in the previous studies on Ce-130,Ce-132,Ce-134, continues in Ce-128. The value of quadrupole def ormation parameter beta(2) deduced from the measured lifetimes is in g ood agreement with the theoretical calculation using a cranking model based on a non-axially deformed Woods-Saxon potential.