Eur. Phys. J. A 10, 21-25
A new alpha-particle-emitting isotope
Z.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 gzg@ns.lzb.ac.cn
qinzhi@ns.lzb.ac.cn
(Received: 7 December 2000 / Revised version: 19 January 2001 Communicated by W. Henning)
Abstract
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