Improved low-energy, electron-spin-polarized 4He+ ion source - Bixler, D. L.; Lancaster, J. C.; Kontur, F. J.; Popple, R. A.; Dunning, F. B.; Walters, G. K. (American Institute of Physics (AIP), 1999)
http://dx.doi.org/10.1063/1.1149572
Keywords: U; ZN