Towards Understanding the Cesium Cycle of the Persistent H{sup -} Beams at SNS

Journal Article · Mon Sep 26 00:00:00 EDT 2011 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3637382· OSTI ID:21611656

Stockli, Martin P; Han, B X; Murray, S N; Pennisi, T R; Santana, M; Welton, R F ^[1]

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1. Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

This paper describes the accomplishments of the SNS H{sup -} ion source, which delivers routinely {approx}50 mA at a 5.4% duty factor with {approx}99% availability, enabling 1 MW beams for neutron production with {approx}90% availability. It discusses the need for increasing reliability and beam current. But mostly it focuses on its unexpected feature: H{sup -} beams that are apparently persistent for up to 5 weeks without adding Cs after an initial dose of less than {approx}5 mg. Thermal emission and sputtering are qualitatively evaluated, and appear consistent with a negligible Cs sputter rate after the initial dose disappears from the Cs plasma. It concludes with a list of future experiments that can shed more light on this apparently unique Cs cycle.

• OSTI ID: 21611656
• Journal Information: AIP Conference Proceedings, Vol. 1390, Issue 1; Conference: 2. international symposium on negative ions, beams and sources, Takayama City (Japan), 16-19 Nov 2010; Other Information: DOI: 10.1063/1.3637382; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

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