Release and efficiencies of radioactive ion beams from the JAEA-ISOL target/ion source systems

摘要

For the ISOL-based radioactive ion beam facility, TRIAC, separation efficiencies and release times of neutron-rich isotopes produced in proton-induced fission of ~(238)U have been measured using the JAEA-ISOL target/ion source systems. With a FEBIAD-B2 type integrated target-ion source, for example, we obtained separation yields, the values were normalized to a uranium target thickness of 1 g/cm~2 and 1 μA primary proton beam current, 1.4 × 10~6 pps for ~(91)Kr, 7 × 10~5 pps for ~(126)In, 2.6 × 10~6 pps for ~(138)Xe, respectively. Using a surface ionization type ion source, under the same normalization, the separation yields of 1.8 × 10~7pps for ~(93)Rb, 6 × 10~7pps for ~(94)Sr, 2.5 × 10~6 pps for ~(143)Cs and 5 × 10~6 pps for ~(142)Ba were observed. The release times of radioactive Rb, Cs, Ba, In, Kr and Xe atoms were measured using present target/ion source systems. Comparison of the measured yields of Ba, In and Xe isotopes with the calculated ones suggests that the long release time gave low separation efficiency for short-lived isotopes.