Method to test the adiabatic operation of a spin one vector polarized ion source

The dependence of the vector polarization produced in the weak field transition region on the direction of the static field gradient is investigated by means of experimental measurements and numerical calculations for a lithium source. The measurements employ a weak field transition apparatus whose tapered magnet is outside the vacuum and hence easily reversed and calculations are performed for several existing polarized ion sources. The results demonstrate that while the vector polarization depends on the direction of the static field gradient under nonadiabatic conditions, this dependence vanishes in the adiabatic limit. It is shown that the positive field gradient consistently produces higher vector polarization and that the independence of the vector polarization on the direction of the field gradient under adiabatic conditions provides a sensitive experimental test of the adiabatic operation of a vector polarized ion source.