Improving efficiency of negative ion production in ion source with saddle antenna

V Dudnikov; R P Johnson; S Murrey; T Pinnisi; C Piller; M Santana; M Stockli; R Welton; C Johnson; M Turvey

doi:10.1063/1.4833021

Improving efficiency of negative ion production in ion source with saddle antenna

Rev Sci Instrum. 2014 Feb;85(2):02B111. doi: 10.1063/1.4833021.

Authors

V Dudnikov¹, R P Johnson¹, S Murrey², T Pinnisi², C Piller², M Santana², M Stockli², R Welton², C Johnson³, M Turvey⁴

Affiliations

¹ Muons, Inc., Batavia, Illinois 60510, USA.
² ORNL, Oak Ridge, Tennessee 37831, USA.
³ Physics Department, Wisconsin University of Madison, Wisconsin 53706, USA.
⁴ Engineering Department, University of Florida, Gainesville, Florida 32611, USA.

PMID: 24593551
DOI: 10.1063/1.4833021

Abstract

Extraction of negative ions from a saddle antenna radio-frequency surface plasma source is considered. Several versions of new plasma generators with different antennas and magnetic field configurations were tested in the smal Oak Ridge National Laboratory Spallation Neutron Source Test Stand. The efficiency of positive ion generation in plasma has been improved to 200 mA/cm(2) kW from 2.5 mA/cm(2) kW. A small oven was developed for cesiation by cesium compounds and alloy decomposition. After cesiation, a current of negative ions to the collector was increased from 1 mA to 10 mA with 1.5 kW RF power in the plasma and longitudinal magnetic field Bl ∼ 250 G. The specific efficiency of H(-) production was increased to 20 mA/cm(2) kW from 2.5 mA/cm(2) kW.