Isomer spectroscopy of neutron rich W-190(116)

Gamma-rays de-exciting a millisecond isomer in the neutron-rich nucleus W-1 90(74)116 have been observed following relativistic projectile fragmentatio n of a I GeV per nucleon Pb-208 beam. Th, isomeric decay populates the grou nd-state rotational band, with energies that indicate a significant deforma tion change at Z = 74 for the N = 116 isotones. The successful application of the projectile fragmentation technique in a region of deformed nuclei op ens up the prospect of exploiting K-isomer decays to probe the evolution of collective nuclear structure far from the valley of beta stability. (C) 20 00 Elsevier Science B.V. All rights reserved.