Production of polarized negative deuterium ion beam with dual optical pumping

To obtain highly vector-spin polarized negative deuterium ion beam, a dual optically pumped polarized negative deuterium ion source has been developed at KEK. It is possible to select a pure nuclear-spin state with this scheme, and negative deuterium ion beam with 100 % nuclear-spin vector polarization can be produced in principle. We have obtained about 70 % of nuclear-spin vector polarized negative deuterium ion beam so far. This result may open up a new possibilities for the optically pumped polarized ion source. (author)