Signatures of shell-effects in collective excitations

Two methods for measuring lifetimes of excited states in nuclei are discussed. One recently developed method involves a plunger device and inverse kinematics Coulomb excitation with heavy beams. The other method covers a different lifetime range and relies on electronic timing. Both methods have recently been applied at Yale University. This paper will give a brief overview of technical aspects of those measurements. A short motivation and preliminary results of the experiments are given.