Polarized gas targets

This review describes the development and present performance of nuclear polarized gas targets in nuclear or particle physics experiments. After a brief account of the various development steps, the design principles for the relevant light nucleon targets, hydrogen, deuterium and 3 He, for storage rings, are discussed. Most of these targets make use of so-called storage cells in order to enhance the target thickness. The performance of targets used in medium and high-energy ion and electron storage rings is reviewed. Finally, future trends and possible improvements are discussed.