Materials for the Synthesis of Superheavy Nuclei: Recent Developments and Prospects

Six new superheavy elements with Z=113-118 have been added to the Periodic Table since 2000. Elements 114-118 were discovered using the “hot fusion” technique, bombarding actinide targets with intense 48Ca beams. To date ~50 isotopes of these elements have been observed in more than 300 decay chains. These results have been dependent on the availability of actinide target materials and adequate supplies of enriched 48Ca. Continued progress in the synthesis of superheavy elements and isotopes is critically dependent on the continued availability of rare actinide materials for targets and stable isotope feedstock for the required ion beams. Actinide materials in the required quantities can only be produced and processed at Oak Ridge National Laboratory (ORNL) and in Russia, and U.S. separation capability to provide the needed stable isotopes (such as 48Ca) is limited.

This presentation will review current capabilities for the production and purification of heavy actinides including Cm, Bk, Cf, and Es, as well as planned and ongoing investments for new facilities for stable isotope enrichment and radioisotope processing at ORNL. These facilities, including ORNL’s High Flux Isotope Reactor, Radiochemical Engineering Development Center, Stable Isotope Production and Research Center (under construction), and planned Radioisotope Processing Facility, are essential to ensure the continued availability of special isotopes for research, medical, national security, and industry applications, including superheavy nuclei research. New developments for producing Bk and other rare actinides as well as enriched stable isotopes important for superheavy research will be discussed. The status of superheavy research from the materials perspective will be reviewed, including prospects for the development and use of new targets and beams.