High Duty Factor (DF) Testing of a Saddle Antenna Radio Frequency Surface Plasma Ion Source (SA RF SPS)

A SA RF SPS was tested at the Spallation Neutron Source (SNS) at Oak Ridge National Lab. Hydrogen ions were extracted from the source as described in Dudnikov et al. (2011).\footnote{Dudnikov, V., et al., AIP Conf. Proc. 1390, 411 (2011).}$^{\mathrm{\thinspace }}$ Modifications were installed to increase ion beam output and optimize cooling. The source was tested under a DF of 5-20\% at 150 Hz as well as a continuous beam with power ranging from 0.8 kW to 3.3 kW. Cesium was also used to optimize H- beam output.\footnote{Dudnikov, V., Method of Negative Ion Production, Patent cccp 411542, 10 March, 1972.}$^{\mathrm{\thinspace }}$ The highest beam produced was 13 mA at 2.5 kW. The SA RF SPS has an ion production efficiency of $\sim$5 mA/kW while the current ion source at the SNS produces $\sim$1 mA/kW.\footnote{Welton, R. F., et.al. AIP Conf. Proc. 925, 87 (2007).}$^{\mathrm{\thinspace }}$ The SA RF SPS will be tested with the conditions of the linear accelerator at the SNS so the recent accelerator-based pulsed neutron record of 20 GW (1.4 MW average power)\footnote{A Record-Breaking Month for ORNL's Spallation Neutron Source www.ornl.gov/ornl/news/features/2014}$^{\mathrm{\thinspace }}$ can be surpassed.