Startup of transactinide chemistry in JAERI

Abstract

The transactinide nuclides²⁶¹Rf and²⁶²Db have been successfully produced in the²⁴⁸Cm(¹⁸O,5n) reaction at 99 MeV and in the²⁴⁸Cm(¹⁹F,5n) reaction at 100, 103, and 106 MeV, respectively, at the JAERI tandem accelerator. The on-line ion exchange experiments with an automated fast and repetitive liquid chromatography separation system were performed in the HNO₃/HF system using Rf homologues^89mZr and^167,165Hf produced in the⁸⁹Y(p,n) and¹⁵²Gd(¹⁸O,xn) reactions, respectively. The radiotracers⁸⁸Zr,¹⁷⁵Hf, and²³⁴Th were also prepared and the distribution coefficients on ion exchange resins were measured systematically in 1-11 M HCl and 1-14 M HNO₃with the batch method. It was found that anion exchange experiments of Rf in 8 M HNO₃and 9 M HCl provided information useful to extract the ionic radius of Rf and to verify the influence of relativistic effects.