Recent studies of unstable nuclei far from stability with the on-line isotope separators of JAERI

Studies on the decay of unstable nuclei using the two on-line isotope separators of JAERI are reviewed for the past five years. With the previously established ion-source technique using mono-oxide ion formation in a thermal ion source, the new nuclides 125Pr and 127Pr have been identified in heavy-ion fusion residues. Further, with a newly developed gas-jet coupled thermal ion source, the new nuclides 166Tb, 165Gd, 161Sm and 236Am have been identified by bombarding 238U and 235U targets with a proton of 6Li beam. Other studies, including off-line experiments, by decay spectroscopy, laser spectroscopy and Moessbauer spectroscopy are described. (author)