An EC-branch in the decay of 27-s 263 Db: Evidence for the isotope 263 Rf

• Published in: Radiochimica acta Vol. 91; no. 1; pp. 59 - 62
• Main Authors: Kratz, J. V., Nähler, A., Rieth, U., Kronenberg, A., Kuczewski, B., Strub, E., Brüchle, W., Schädel, M., Schausten, B., Türler, A., Gäggeler, H. W., Jost, D. T., Gregorich, K. E., Nitsche, H., Laue, C., Sudowe, R., Wilk, P. A.
• Format: Journal Article
• Language: English
• Published: 01.01.2003
• ISSN: 0033-8230; 2193-3405
• DOI: 10.1524/ract.91.1.59.19010

Summary 27-s 263 Db was produced in the 249 Bk ( 18 O, 4 n ) reaction at 93 MeV. The activity was transported by a He/KCl-jet to the laboratory where it was collected for 15 min and then subjected to a chemical separation specific for group-4 elements. The activity was dissolved in 0.5 M unbuffered α -HiB and eluted from a cation-exchange column. The effluent was made 9 M in HCl and group-4 tetrachlorides were extracted into TBP/Cyclohexane which was evaporated to dryness on a Ta disc. The Ta discs were assayed for α and SF activity. A SF activity with a half life on the order of 20 min was observed and assigned to the nuclide 263 Rf. It is formed by electron-capture decay of 263 Db with a decay branch of 3 +4 -1 %.