The new BNL polarized negative ion source

A new ground state source of negative hydrogen ions with polarized nuclei (r-vector H(-)) is being developed at BNL. Extensive developmental research has been aimed at improving each element of r-vector H(-) production: cold H(0) beam, spin selection and focusing magnets, and ionizer. These elements have recently been integrated into a source. A first test with the accommodator nozzle cooled only to liquid nitrogen temperatures resulted in 5 micro-A of H(-). Tests at liquid helium temperatures are being initiated.