In-beam conversion-electron spectroscopy of 180Hg

Excited states in Hg-180 were populated using the Sm-147(Ar-36,3n)Hg-180 reaction and studied by in-beam conversion-electron spectroscopy. Conversion electrons emitted at the target position were measured using the Silicon Array for Conversion Electron Detection (SACRED) spectrometer and tagged through the characteristic alpha decays of Hg-180 detected in a position-sensitive silicon strip detector located at the focal plane of the gas-filled recoil separator Recoil Ion Transport Unit (RITU). Electron conversion of transitions previously assigned to Hg-180 through in-beam gamma-ray spectroscopy studies was identified up to the 10(+) -> 8(+) transition and the intensities of the conversion-electron transitions were found to be consistent with the previous multipolarity assignments. Evidence was also found for two highly converted transitions in Hg-180: a 167 keV transition is interpreted as the transition from the newly identified 2(2)(+) state at 601 keV to the 2(1)(+) state at 434 keV, while a 420 keV transition is assigned as the E0 decay from the 0(+) bandhead of the prolate-deformed configuration to the weakly deformed ground state.