Spin-polarization of radioactive 123 In g.s. by the tilted-foil method

A spin-polarized radioactive 123 In ( I π , g = 1.220(2) , T 1/2 = 5.97(5) s) beam has been successfully generated by the tilted-foil method. This nuclide is the heaviest ever polarized in its ground state by this method. Using the ISOL-based re-acceleration-type facility TRIAC, an 123 In g.s. beam of 305 keV/nucleon went through a stack of 15 carbon foils with a tilt angle of 70 ° , and an asymmetry of 0.76 ± 0.25% of β -decays was observed by the β -NMR technique. The asymmetry shows that the tilted-foil method combined with a re-acceleration facility is useful for producing spin-polarized beams for applications such as nuclear physics and materials science.