Polarized radioactive ion beams

Radioactive beams are short-lived heavy-ion beams which can be polarized using in-flight techniques. Methods commonly used are based on tilted foils or recoil angle selection at high energies, or laser optical pumping at low energies. Tilted foils are a universal method typically producing nuclear polarization of a few percent. Recoil selection produces appreciable polarization under some conditions. Collinear optical pumping of alkali beams typically produces much higher polarization. The latter technique and its extension to the alkaline earths, noble gases and other elements are described.