RF Conditioning and Testing of Fundamental Power Couplers for SNS Superconducting Cavity Production

• Published in: Proceedings of the 2005 Particle Accelerator Conference pp. 4132 - 4134
• Main Authors: Stirbet, M., Wilson, K.M., Wiseman, M., Henry, J., Drury, M., Davis, G.K., Grenoble, C., Powers, T., Myneni, G., Campisi, I.E., Kang, Y., Stout, D.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 2005
• Subjects: Assembly; Couplers; Klystrons; Neutrons; Production; Quality assessment; Radio frequency; Reflection; Superconducting devices; Testing
• ISBN: 9780780388598; 0780388593
• ISSN: 1944-4680; 2152-9582
• DOI: 10.1109/PAC.2005.1591741

The Spallation Neutron Source (SNS) makes use of 33 medium beta (0.61) and 48 high beta (0.81) superconducting cavities. Each cavity is equipped with a fundamental power coupler, which should withstand the full klystron power of 550 kW in full reflection for the duration of an RF pulse of 1.3 msec at 60 Hz repetition rate. Before assembly to a superconducting cavity, the vacuum components of the coupler are submitted to acceptance procedures consisting of preliminary quality assessments, cleaning and clean room assembly, vacuum leak checks and baking under vacuum, followed by conditioning and RF high power testing. Similar acceptance procedures (except clean room assembly and baking) were applied for the airside components of the coupler. All 81 fundamental power couplers for SNS superconducting cavity production have been RF power tested at JLAB Newport News and, beginning in April 2004 at SNS Oak Ridge. This paper gives details of coupler processing and RF high power-assessed performances.