Polarized He Ion Source for a CN Van de Graaff

It is shown that it is possible to produce directly in an R.F. ion source 260 nA of 3He+(2S) ions, which can be subsequently polarized by a Lamb Shift method. The ion source has to operate with a low extraction voltage gradient to avoid quenching of the metastable 2S state. It is possible to estimate a final on target current of 100 nA of polarized 3He++ ions with 70% polarization utilizing the Sona adiabatic transition and strong field ionization.