No abstract

Recent improvements to a source of electron-spin-polarized He+4 ions based on an optically pumped, rf-excited helium discharge are described that have resulted in ion polarizations P+ of ∼0.18 at currents of ∼1 nA and in an increase of over an order of magnitude in the quality factor P+2I.

Use of a commercial 1.083 μm laser diode to optically pump a collimated He (23S) metastable atom beam is described. Stable, efficient optical pumping is achieved resulting in polarizations that approach 100%.

A source of low-energy, electron-spin-polarized 4 He ϩ ions based on an optically pumped, rf-excited helium discharge is described. Ion polarizations P ϩ of ϳ0.13 are achieved at beam currents of ϳ0.1 nA, decreasing to ϳ0.09 at currents of ϳ0.5 nA. Ion beam energies as low as 10 eV have been realized, with an energy spread of Շ3 eV full width half maximum. The ion polarization can be reversed ( P ϩ →Ϫ P ϩ ) simply by changing the sense of circular polarization of the optical pumping radiation. The source is suitable for use in a wide variety of applications including surface physics studies.

A polarized internal 3He target using optical pumping of metastable atoms AIP Conf.