Development of Polarized Hydrogen Ion Source with Resonant Charge-Exchange Plasma Ionizer at INR, Moscow

Density of unpolarized negative ions in a charge-exchange region of a plasma ionizer of polarized ion source of INR, Moscow has been increased significantly due to development of a two-stage converter of plasma particles into negative ions. Unpolarized D^- ion current with a peak intensity of 45 mA has been obtained from the plasma ionizer with the two-stage converter. Respectively, polarized H^- ion current of 2.5 mA peak with pulse duration of 150 μs at 5 Hz rep. rate has been obtained. Further increase of unpolarized negative ion density in the charge-exchange region has been achieved due to improvements in the plasma source design. 90 mA of unpolarized D^- ion current and 150 mA of unpolarized H^- ion current have been extracted recently from the ionizer. Problems that are necessary to overcome for corresponding increase of polarized ion beam intensity are discussed. It is expected that 4 mA of polarized H^- ion current will be obtained from the source after implementation of the improvements described.