A pulse-operated polarized H- source of Lamb-shift type

A pulse-operated polarized H- source of the Lamb-shift type has been developed at the National Laboratory for High Energy Physics in Japan (KEK) for future acceleration of polarized protons in the KEK 12 GeV proton synchrotron. A new spin selection principle proposed by Donnally has been adopted, in which only the hyperfine substate of 2Ssub(1/2) with zero total angular momentum is selected by causing the transitions of the other three substates of 2Ssub(1/2) to 2Psub(1/2) by an rf electric field making an angle of about 500 with the direction of a weak static magnetic field. In the preliminary experiments, a 350 nA H- beam of about 60% polarization has been obtained. (Auth.)