Cavity Production and Testing of the First C75 Cryomodule for CEBAF

Conference · Wed Jun 01 04:00:00 EDT 2022

DOI:https://doi.org/10.2172/1905295· OSTI ID:1905295

Ciovati, G. ^[1]; Cheng, G. ^[1]; Daly, E. ^[1]; Davi, G. K. ^[1]; Drury, M. A. ^[1]; Fischer, J. F. ^[1]; Forehand, D. ^[1]; Macha, K. ^[1]; Marhauser, F. ^[1]; McEwen, E. A. ^[1]; Mitchell, A. L. ^[1]; Reilly, A. V. ^[1]; Rimmer, R. A. ^[1]; Wang, S. ^[1]

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1. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

The CEBAF cryomodule rework program was updated over the last few years to increase the energy gain of refurbished cryomodules to 75 MeV. The concept recycles the waveguide end-groups from original CEBAF cavities fabricated in the 1990s and replaces the five elliptical cells in each with a new optimized cell shape fabricated from large-grain, ingot Nb material. Eight cavities were fabricated at Research Instruments, Germany, and two cavities were built at Jefferson Lab. Each cavity was processed by electropolishing and tested at 2.07 K. The best eight cavities were assembled into ’cavity pairs’ and re-tested at 2.07 K, before assembly into the cryomodule. All but one cavity in the cryomodule were within 10% of the target accelerating gradient of 19 MV/m with a quality factor of 8·10⁹. The performance limitations were field emission and multipacting.

• Research Organization: Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• DOE Contract Number: AC05-06OR23177
• OSTI ID: 1905295
• Report Number(s): JLAB-ACC-21-3461; DOE/OR/23177-5661
• Country of Publication: United States
• Language: English