For the first time, chemical separations of element 106 (Seaborgium, Sg) were performed in aqueous solutions. The isotopes 265 Sg and 266 Sg were produced in the 248 Cm + 22 Ne reaction at a beam energy of 121 MeV. The reaction products were continuously transported by a He(KCl)-jet to the computer-controlled liquid chromatography system ARCA. In 0.1 M HNO3/5 X ΙΟ -4 M HF, Sg was found to be eluted within 10 s from 1.6X8 mm cation-exchange columns (Aminex A6, 17.5±2 μπι) together with the hexavalent Mo-and W-ions, while hexavalent U-ions and tetravalent Zr-, Hf-, and element 104 ions were strongly retained on the column. Element 106 was detected by measuring correlated α-decays of the daughter isotopes 78-s 261 104 and 26-s 257 102. For the isotope 266 Sg, we have evidence for a spontaneous fission branch. It yields a partial spontaneousfission half-life which is in agreement with recent theoretical predictions. The chemical results show that the most stable oxidation state of Sg in aqueous solution is +6, and that like its homologs Mo and W, Sg forms neutral or anionic oxo-or oxohalide-compounds under the present condition. In these first experiments, Sg exhibits properties very characteristic of group 6 elements, and does not show U-like properties.

The therapeutic radionuclide 47Sc was produced through the 48Ca(p,2n) channel on a proton beam accelerator. The obtained results show that the optimum proton energies are in the range of 24–17 MeV, giving the possibility to produce 47Sc radionuclide containing 7.4% of 48Sc. After activation, the powdery CaCO3 target material was dissolved in HCl and scandium isotopes were isolated from the targets. The performed separation experiments indicate that, due to the simplicity of the operations and the chemical purity of the obtained 47Sc the best separation process is when scandium radioisotopes are separated on the 0.2 µm filter.

Seaborgium / Element 106 / Aqueous chemistry / HydrolysisSummary Seaborgium was previously eluted from cation exchange columns like its homologs molybdenum and tungsten in 0.1 Μ HNO3/5 Χ 10" 4 Μ HF. Its chemical form was presumably a neutral or anionic oxygen containing fluoride. However, species containing no fluoride such as SgOJ" could not be excluded. In order to verify that fluoride complexing played a role in the previous study, another series of cation exchange separations was performed with 7-s 265 Sg in which 0.1 Μ HN0 3 without HF was used as eluent. 265 Sg and ,69 W were produced simultaneously by bombarding a 248 Cm target containing Gd with 124 MeV 22 Ne ions. While 169 W was eluted from the cation exchange columns with an average chemical yield of 59%, no 265 Sg decay chain was detected in the eluent even though about 5 aacorrelations were expected. This non-tungsten like behaviour of seaborgium is tentatively attributed to its lower tendency to hydrolyze compared to that of tungsten. In the previous experiments with seaborgium in the presence of fluoride ions, neutral or anionic fluoride complexes, e.g., Sg0 2 F 2 or SgC^Fä, were likely to be formed and were eluted from the cation exchange columns.

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