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

Murakami, Masashi*  ; Goto, Shinichi*; Murayama, Hirofumi*; Kojima, Takayuki*; Kudo, Hisaaki*; Kaji, Daiya*; Morimoto, Koji*; Haba, Hiromitsu*; Kudo, Yuki*; Sumita, Takayuki*; Sakai, Ryutaro*; Yoneda, Akira*; Morita, Kosuke*; Kasamatsu, Yoshitaka*; Kikunaga, Hidetoshi*; Sato, Tetsuya   

Production cross sections of Rf isotopes in the Cm + O 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 Rf, Rf, and Rf were obtained together with those of spontaneously fissioning nuclides which have few-second half-lives and have been assigned to Rf and a longer-lived state of Rf. The excitation function of few-second spontaneously fissioning nuclide exhibited the maximum cross section at the O beam energy of 94.8 MeV. The shape of the excitation function was almost the same as that of Rf, whereas it was quite different from those of Rf and Rf. A few-second spontaneously fissioning nuclide previously reported as Rf and Rf observed inCm + O reaction was identified as Rf.