Abstract
Two isomeric states of Sg, i.e., Sg and Sg, proposed in Ch. E. Düllmann and A. Türler [Phys. Rev. C 77, 064320 (2008)] were produced in the Cm(Ne,5)Sg reaction. Decay properties of Sg were investigated with a rotating-wheel apparatus for and spontaneous fission (SF) spectrometry under low background conditions attained by a gas-jet transport system coupled to the RIKEN gas-filled recoil ion separator. Based on genetically correlated -(-) and -SF decay chains, 18 and 24 events were assigned to Sg and Sg, respectively. The half-life and -particle energy of Sg were measured to be 8.5 s and 8.84 0.05 MeV, respectively, and those of Sg were 14.4 s and 8.69 0.05 MeV. As a daughter product of Sg, the decay properties of the 3-s isomeric state in Rf, i.e., Rf, were also derived: 2.6 s, 8.51 0.06 MeV, and SF branch 0.82 0.09. These results confirm and refine the decay pattern suggested for the decay chain Hs Sg Rf No in Düllmann and Türler. The production cross sections for Sg and Sg were determined to be 180 and 200 pb at 117.8 MeV, respectively, and they are discussed by comparing with the literature data as well as the theoretical prediction.
- Received 20 December 2011
DOI:https://doi.org/10.1103/PhysRevC.85.024611
©2012 American Physical Society