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 E_lab =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.

PACS
21.10.Tg - Lifetime.
21.60.Cs - Shell model.
27.90.+b - .

© Società Italiana di Fisica, Springer-Verlag 2001