Lifetimes of eight high spin states were measured in the yrast band of even-even nucleus ${}^{80}\mathrm{Kr}$ by Doppler shift attenuation method. High spin states were populated by the heavy ion fusion evaporation reaction ${}^{65}\mathrm{Cu}{(}^{19}\mathrm{F}{,2p2n)}^{80}\mathrm{Kr}.$ The transition quadrupole moments, extracted from the lifetimes of the states, show a decreasing tendency after the band crossing indicating a change in shape of ${}^{80}\mathrm{Kr}$ at high spin. The total Routhian surface calculations, using Woods-Saxon mean field potential and BCS pairing with Strutinsky shell correction procedure, predict a change from a near oblate to near prolate shape with small deformation along the yrast band at high spin in ${}^{80}\mathrm{Kr}.$ The present experimental $Q_t$ values and the second alignment in the yrast band of ${}^{80}\mathrm{Kr}$ support the predicted change in shape.

• Received 11 June 2000

DOI:https://doi.org/10.1103/PhysRevC.64.034316