Electron-Spin-Polarized Targets for a Collisionally-Pumped Polarized-Ion Source

Collisional pumping has been proposed as a mechanism for producing polarized ion beams more intense by orders of magnitude than those from the best existing sources. One implementation of this method employs a very thick electron-spin-polarized alkali-vapor target in a low magnetic field, and is characterized by a predicted 100% spin-transfer efficiency from the target to the beam. Target characteristics and design constraints are discussed.