1.
Rev Sci Instrum
; 83(2): 02A732, 2012 Feb.
Article
in English
| MEDLINE
| ID: mdl-22380241
ABSTRACT
Since 2009, the Spallation Neutron Source (SNS) has been producing neutrons with ion beam powers near 1 MW, which requires the extraction of â¼50 mA H(-) ions from the ion source with a â¼5% duty factor. The 50 mA are achieved after an initial dose of â¼3 mg of Cs and heating the Cs collar to â¼170 °C. The 50 mA normally persist for the entire 4-week source service cycles. Fundamental processes are reviewed to elucidate the persistence of the SNS H(-) beams without a steady feed of Cs and why the Cs collar temperature may have to be kept near 170 °C.