alpha decay of the very neutron-deficient isotopes Fr197-199

作者：Kalaninova Z^*; Andreyev A N; Antalic S; Hes**erger F P; Ackermann D; Andel B; Drummond M C; Hofmann S; Huyse M; Kindler B; Lane J F W; Liberati V; Lommel B; Page R D; Rapisarda E; Sandhu K; Saro S; Thornthwaite A; Van Duppen P

来源：Physical Review C, 2013, 87(4): 044335.

DOI：10.1103/PhysRevC.87.044335

Decay properties of the very neutron-deficient isotopes Fr197-199 were studied at the velocity filter Separator for Heavy Ion reaction Products (SHIP) at GSI in Darmstadt. The isotopes were produced in the 2n-4n evaporation channels of the fusion-evaporation reaction Ni-60 + Pr-141 -%26gt; Fr-201*. Improved alpha-decay properties of Fr-199 were determined and the possible existence of two alpha-decaying states in this nucleus is discussed. For the isotope Fr-198 a broad alpha-decay energy distribution was detected in the range of (7470-7930) keV and two alpha-decaying states were observed with half-lives of 1.1(7) and 15(3) ms. The new isotope Fr-197 was identified based on the observation of one alpha-decay chain yielding E-alpha = 7728(15) keV and T-1/2 = 0.6(0.3)(vertical bar 3.0) ms. The systematics of reduced alpha-decay widths are presented for neutron-deficient francium, radon, and astatine isotopes.

• 出版日期2013-4-29