Eur. Phys. J. A 10, 21-25
A new alpha-particle-emitting isotopeZ.G. Gan, Z. Qin, H.M. Fan, X.G. Lei, Y.B. Xu, J.J. He, H.Y. Liu, X.L. Wu, J.S. Guo, X.H. Zhou, S.G. Yuan and G.M. Jin
Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, P.R. China email@example.com
(Received: 7 December 2000 / Revised version: 19 January 2001 Communicated by W. Henning)
An isotope of the element 105 with mass number 259 has been produced via the reaction 241Am(22Ne, 4n)259Db at Elab =118 MeV. The reaction products were transported and collected using the helium-jet technique and the rotating wheel apparatus. The -decays of the products and their daughter nuclides were detected by a set of Si(Au) detectors arranged ingeniously. The Z and A of the nuclide have been unambiguously identified by the genetic relationship between the new activity and the known nuclide 255Lr established by -recoiled milking measurement. The new nuclide 259Db has a half-life of s and decays by alpha-particle emission of MeV. Furthermore, the nuclide 258Db and its daughter 254Lr have also been clearly observed using the same projectile-target combination. Their half-lives and -particle energies determined in this work are in agreement with previous known data, thus also proving the reliability of our assignment of 259Db.
21.10.Tg - Lifetime.
21.60.Cs - Shell model.
27.90.+b - .
© Società Italiana di Fisica, Springer-Verlag 2001