Superheavy element chemistry at GARIS

A gas-jet transport system has been installed to the RIKEN GAs-filled Recoil Ion Separator, GARIS to start up SuperHeavy Element (SHE) chemistry. This system is a promising approach for exploring new frontiers in SHE chemistry: background radioactivities from unwanted by-products are suppressed, a high gas-jet transport yield is achieved, and new chemical reactions can be investigated. Useful radioisotopes of ²⁶¹Rf^a,b, ²⁶²Db, and ²⁶⁵Sg^a,b for chemical studies were produced in the reactions of ²⁴⁸Cm(¹⁸O,5n)²⁶¹Rf^a,b, ²⁴⁸Cm(¹⁹F,5n)²⁶²Db, and ²⁴⁸Cm(²²Ne,5n)²⁶⁵Sg^a,b, respectively. They were successfully extracted to a chemistry laboratory by the gas-jet method. Production and decay properties of ²⁶¹Rf^a,b, ²⁶²Db, and ²⁶⁵Sg^a,b were investigated in detail with the rotating wheel apparatus for α- and spontaneous fission spectrometry. Present status and perspectives of the SHE chemistry at GARIS are also briefly presented.