Discovery of doubly-magic Ni-48 at GANEL

An experiment was performed at GANIL using a high-intensity Ni-58 beam at 74.5 MeV/nucleon on a nickel target. The projectile fragments produced in the high-acceptance SISSI device were selected in the LISE3 spectrometer using the Wien filter. The detection setup performed an unambiguous identification of four Ni-48 implantation events. A lower limit of its half-life of the order of 0.5 mus and an estimate of the production cross section of about 0.05 pb were deduced. In addition, a few tens of Fe-45 and Ni-49 nuclei were implanted, which may give information on their decay modes. Besides, Ni-48 and Fe-45 are very good candidates for two-proton radioactivity, still to be observed. (C) 2002 Elsevier Science B.V. All rights reserved.