NRC-8, EuCheMS International Conference on Nuclear and Radiochemistry

ORAL PRESENTATION - New experiments to study properties of ²⁶⁸Db produced in the ⁴⁸Ca + ²⁴³Am reaction

18 Sept 2012, 10:25

15m

Como, Italy

Oral Communications Chemistry of radioelements and Super Heavy Elements research Session 3 - Chemistry of radioelements and Super Heavy Elements research

Speaker

Dr Nikolay Aksenov (Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, Russia)

Description

We conducted a new round of experiments to isolate and study chemical properties of 268Db, the end product of 288115 synthesized in a 48Ca + 243Am reaction. In contrast to previous experiments [1, 2] the reaction products passed through a gas filled recoil separator (DGFRS) and were stopped in a catcher (copper foil) which provided an additional separation from the actinides with a decontamination factor of 4 – 5 orders of magnitude. The chemical separation procedures have been developed for selective isolation of Db from the catcher using coprecipitation with LaF3 [3], ion-exchange and extraction chromatography from HF and HCl solutions. Altogether 8 spontaneous fission events were detected with a half-life of 23+13-6 hour. The cross-section for the production of 288115 was found to be 6+3.6-2.4 pb. This is in agreement with the previously reported data [1, 2, 4]. According to all previous experiments the half-life of spontaneously decaying nuclide 268Db was estimated to be 27.4+4.6-3.4 hour. Also the extraction behavior of Db together with those of the lighter group-5 elements Nb and Ta into UTEVA resin was investigated in 2 – 5.5 M HCl solutions by reversed-phase extraction chromatography. The obtained order of extraction Nb > Ta > Db suggests that stability of the chloride complex of Db is lower than those of Nb and Ta. The work was supported by Russian Foundation for Fundamental Research (project code 11-03-12058-ofi-m). [1] S.N. Dmitriev et al., Mendeleev Communications 15, 1, 1 (2005). [2] N.J. Stoyer et al., Nuclear Physics A 787, 388-395 (2007). [3] N.V. Aksenov et al., Phys. Part. Nuclei Letters 8, 4, 356-363 (2011). [4] Yu.Ts. Oganessian et al. Phys. Rev. Lett. 108, 022502 (2012).