2019 Impact factor 2.176
Hadrons and Nuclei

Eur. Phys. J. A 10, 21-25

A new alpha-particle-emitting isotope $\mathsf{^{259}Db}$

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


(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 $\alpha $-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 $\alpha $-recoiled milking measurement. The new nuclide 259Db has a half-life of $0.51\pm
0.16$ s and decays by alpha-particle emission of $E_\alpha =9.47$ MeV. Furthermore, the nuclide 258Db and its daughter 254Lr have also been clearly observed using the same projectile-target combination. Their half-lives and $\alpha $-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 - $A\geq 220$ .

© Società Italiana di Fisica, Springer-Verlag 2001