Decay of proton-rich nuclei between 39Ti and 49Ni

Decay studies of very neutron-deficient nuclei ranging from 39Ti to 49Ni have been performed during a projectile fragmentation experiment at the GANIL/LISE3 separator. For all nuclei studied in this work, 39,40Ti, 42,43Cr, 46Mn, 45,46,47Fe and 49Ni, half-lives and decay spectra have been measured. In a few cases, gamma coincidence measurements helped to successfully identify the initial and final states of transitions. In these cases, partial decay scheme are proposed. For the most exotic isotopes, 39Ti, 42Cr, 45Fe and 49Ni, which are candidates for two-proton radioactivity from the ground state, no clear evidence of this process is seen in our spectra and we conclude rather on a delayed particle decay.Comment: 12 pages, 15 figures, submitted for publication in Eur. Phys. J.

First observation of 55,56Zn

In an experiment at the SISSI/LISE3 facility of GANIL, the most proton-rich zinc isotopes 55,56Zn have been observed for the first time. The experiment was performed using a high-intensity 58Ni beam at 74.5 MeV/nucleon impinging on a nickel target. The identification of 55,56Zn opens the way to 54Zn, a good candidate for two-proton radioactivity according to theoretical predictions.Comment: 2 pages, 1 figure, accepted for publication in Eur. Phys. J.

Isomers in neutron-rich A approx 190 nuclides from 208Pb fragmentation

Relativistic projectile fragmentation of 208Pb has been used to produce isomers in neutron-rich, A appro 190 nuclides. A forward-focusing spectrometer provided ion-by-ion mass and charge identification. The detection of γ-rays emitted by stopped ions has led to the assignment of isomers in 188Ta, 190W, 192}Re, 193Re, 195Os, 197r, 198Ir, 200Pt, 201Pt, 202Pt and 203Au, with half-lives ranging from approximately 10 ns to 1 ms. Tentative isomer information has been found also for 174Er,175Er, 185Hf, 191Re, 194Re and 199Ir. In most cases, time-correlated, singles γ-ray events provided the first spectroscopic daa on excited states for each nuclide. In 200Pt and 201Pt, the assignments are supported by γ-γ coincidences. Isomeric ratios provide additional information, such as half-life and transition energy constraints in particular cases. The level structures of the platinum isotopes are discussed, and comparisons are made with isomer systematics