Stabilized operation of the Spallation Neutron Source radio-frequency quadrupole

• Main Authors: Sang-ho Kim, Alexander Aleksandrov, Mark Crofford, John Galambos, Paul Gibson, Tom Hardek, Stuart Henderson, Yoon Kang, Kay Kasemir, Charles Peters, David Thompson, Martin Stockli, Derrick Williams
• Format: Article
• Language: English
• Published: American Physical Society 2010-07-01
• Series: Physical Review Special Topics. Accelerators and Beams
• Online Access: http://doi.org/10.1103/PhysRevSTAB.13.070101

The Spallation Neutron Source (SNS) radio-frequency quadrupole (RFQ) had resonance control instabilities at duty factors higher than approximately 4%. Systematic investigations have been carried out to understand the cause of the instability and to ensure the operational stability of the RFQ. The most critical source of the instability is revealed to be an interaction between hydrogen released by beam bombardments and the RFQ rf field resulting in a discharge, which consumes additional rf power and could cause the RFQ to operate in an unstable region. This paper reports improvement of the SNS RFQ operational stability based on the findings during the SNS operation.