Collisional pumping in polarized sodium vapor

Collisional pumping has been proposed as a mechanism for efficient transfer of spin from an electron-spin-polarized target to the nuclei of a fast atom or ion beam. Collisional pumping takes place in low magnetic fields, can give polarization transfer approaching 100%, and offers the potential for producing polarized beams orders of magnitude more intense than presently achieved. Recently reported calculations of electronic spin-exchange cross sections at useful ion-source energies suggest significantly greater rates of pumping than first estimated, and give cause for increased optimism about sucessful implementation. Collisional pumping is described, and beam characteristics are given for prototype polarized source parameters