Lifetimes of yrast rotational states of the fission fragments 100Zr and 104Mo measured using a differential plunger

Abstract

Lifetime measurements have been performed for yrast rotational states of 100Zr and 104Mo using a 252Cf source in a differential plunger arrangement, together with the EUROBALL and SAPHIR multi-detector arrays. The system has been proved capable of covering a range of lifetimes from a nanosecond to a picosecond. The transition quadrupole moments are found to decrease by around 20% between I = 4 and I = 8 in the case of 104Mo while remaining constant in 100Zr. The origin of this effect lies either in a rotation-induced shape change, or in the strong mixing between the ground and s-bands in 104Mo.