RESULTS OF THE EXPERIMENT FOR CHEMICAL IDENTIFICATION OF Db AS A DECAY PRODUCT OF ELEMENT 115

Chemical studies of elements with Z≥ 104 in liquid phase

“…Then the effluent was evaporated and deposited onto a polyethylene foil with subsequent drying in a stream of warm He gas. All procedures starting from the EOB until the beginning of detector measurements took 2-3 h[68][69][70].In the eight irradiation samples, 15 spontaneous fission, SF, events were detected within 174 h. A decay analysis resulted in a single component with a half-that agrees with T 1/2 obtained in the separate physical experiment[71] within statistical errors. A cross section for the production of the long-lived SF nuclide from, presumably 243 Am( 48 Ca, 3n) 288 115, was reported to be about 4 pb[68][69][70].…”

“…All procedures starting from the EOB until the beginning of detector measurements took 2-3 h[68][69][70].In the eight irradiation samples, 15 spontaneous fission, SF, events were detected within 174 h. A decay analysis resulted in a single component with a half-that agrees with T 1/2 obtained in the separate physical experiment[71] within statistical errors. A cross section for the production of the long-lived SF nuclide from, presumably 243 Am( 48 Ca, 3n) 288 115, was reported to be about 4 pb[68][69][70]. Schumann et al concluded that the observed nuclide forms a hydroxide in ammonium solution coprecipitating with La(OH)3 and forms strong anionic fluoride complexes in HF solution, indicating that its chemical properties correspond to that of a group 4 or 5 element[69].…”

“…9. As discussed in [65] Recently, chemical identification of Db as a decay product of element 115 produced in the reaction 243 Am + 48 Ca was performed [68][69][70]. A 32-cm 2 rotating target consisting of the enriched isotope 243 Am in the oxide form was bombarded by a 247-MeV 48 Ca beam at the U-400 cyclotron at the Flerov Laboratory of Nuclear Reactions (FLNR), Dubna, Russia.…”

Discovery of the elements with atomic numbers greater than or equal to 113 (IUPAC Technical Report)

“…115; 02 The collaboration of Dmitriev et al [14,15] The collaboration of Dmitriev et al [14,15] at the Flerov Laboratory in Dubna used the 48 Ca + 243 Am fusion reaction in 2004 to produce 15 additional spontaneous fission nuclides and other reaction products recoiling directly, without selectivity, onto a copper surface from which they were extracted and subjected to chemical separations. The technique employed was claimed to distinguish between Group 3 elements (lanthanides and actinides) and combined Groups 4 and 5.…”

Discovery of the elements with atomic numbers Z = 113, 115 and 117 (IUPAC Technical Report)

“…The collaboration of Dmitriev et al [24,25] Am fusion reaction in 2005 to produce 15 additional spontaneous fission nuclides and other reaction products recoiling directly, without selectivity, onto a copper surface from which they were extracted and subjected to cation exchange separation. The technique employed was claimed to distinguish between Group 3 elements (lanthanides and actinides) and combined Groups 4 and 5.…”