Excitation functions for production of Rf isotopes in the 248Cm+18O reaction

Production cross sections of Rf isotopes in the 248Cm+18O reaction were measured at the beam energy range of 88.2 to 101.3 MeV by use of a gas-filled recoil ion separator. The excitation functions of 260Rf, 261Rfa, and 262Rf were obtained together with those of spontaneously fissioning nuclides which have few-second half-lives and have been assigned to 261Rfb and a longer-lived state of 262Rf. The excitation function of few-second spontaneously fissioning nuclide exhibited the maximum cross section at the 18O beam energy of 94.8 MeV. The shape of the excitation function was almost the same as that of 261Rfa, whereas it was quite different from those of 260Rf and 262Rf. A few-second spontaneously fissioning nuclide previously reported as 261Rfb and 262Rf observed in 248Cm+18O reaction was identified as 261Rfb.