A review is given on the startup of the superheavy element (SHE) chemistry at RIKEN. A gas-jet transport system for the SHE chemistry has been coupled to the gas-filled recoil ion separator GARIS at the RIKEN Linear Accelerator. The performance of the system was appraised using 206Fr and 245Fm produced in the 169Tm (40Ar, 3n) 206Fr and 208Pb (40Ar, 3n) 245Fm reactions, respectively. The α particles of 206Fr and 245Fm separated with GARIS and transported by the gas-jet were identified with a rotating wheel system for α spectrometry under desired low background condition. The high gas-jet efficiencies over 80% were independent of the beam intensities up to 2 particle μA. A gas-jet coupled target system for the production of SHEs was also installed on the beam line of the RIKEN K70 AVF cyclotron. The gas-jet transport of 255No and 261Rf produced in the 238U (22Ne, 5n) 255No and 248Cm (18O, 5n) 261Rf reactions, respectively, was conducted for the future chemical studies of 265Sg via the 248Cm (22Ne, 5n) 265Sg reaction.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics