Development of new methods for aqueous chemistry on element 104, rutherfordium: Batchtype solid-liquid extraction and coprecipitation

Abstract

Rapid chemical experiment targeting single atoms combined with identification via alpha-particle measurement is required for superheavy element chemistry. Herein, successful development of two types of experimental methods of superheavy element chemistry: solid-liquid extraction and precipitation, is presented. The chemical behaviors of Zr and Hf (homologues of element 104, Rf), and Th (pseudo homologue) were investigated using carrier-free RI tracers. Through these studies, rapid chemical reaction systems were found and the comparative data to discuss the chemical properties of Rf were obtained. In addition, automated chemistry apparatuses for extraction and precipitation were developed and their performance was evaluated using the short-lived isotopes of Zr and Hf, which were transported online from the nuclear reaction chamber in the accelerator room by a He/KCl gas-jet system. From those results, the newly developed methods were both found to be applicable to ²⁶¹Rf experiments, and suitable experimental conditions to study the chloride complexation (solid-liquid extraction) and hydroxide complexation (coprecipitation) of Rf were determined.