Preliminary Cryogenic Cold Test Results of the First 9-Cell LSF Shape Cavity

Conference · Sat May 01 04:00:00 EDT 2021

OSTI ID:1831667

Geng, Rong-Li ^[1]; Celemens, William A. ^[2]; Williams, Scott ^[2]; Hayano, Hitoshi ^[3]; Iwashita, Yoshihisa ^[4]; Fuwa, Yasuhiro ^[5]; Li, Zenghai ^[6]; Belomestnykh, Sergey ^[7]; Shemelin, Valery D. ^[8]

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1. ORNL
2. Thomas Jefferson National Accelerator Facility (Jefferson Lab)
3. High Energy Accelerator Research Organization, KEK
4. Kyoto University Institute for Chemical Research Advanced Research Center for Beam Science
5. Japan Atomic Energy Agency J-PARC Center
6. SLAC National Accelerator Laboratory
7. Fermi National Accelerator Laboratory (FNAL)
8. Cornell University Laboratory for Accelerator-Based Sciences and Education

Following successful prototyping and testing of single- & 5-cell LSF shape cavities *, **, the first 9-cell LSF shape cavity LSF9-1 was successfully constructed using an innovative process at JLab with the in-house facilities. The cavity was then shipped to KEK for post-fabrication mechanical adjustment and ILC TDR style treatment and surface processing. Cold testing was carried out at the JLab VTA facility, instrumented with a suite of Kyoto instruments. Favorable values for the bath pressure detuning sensitivity and Lorentz force detuning coefficient were experimentally measured, validating the design improvement in cell stiffeners. Pass-band measurements indicate 4 out of 9 cells reaching gradient capability of > 45 MV/m, including 2 cells reaching 51 MV/m. Cornell OST detectors identified the cell and location responsible for the current hard quench limit. Multipacting-like barriers observed in end cells are investigated both analytically and numerically. The cavity was shipped to FNAL and received a light EP at the joint ANL/FNAL facility for further cold testing at Jlab. Two new 9-cell LSF cavities are being constructed including one made of large-grain niobium material.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1831667
• Country of Publication: United States
• Language: English