Mechanical Performance of the First Two Prototype 4.5 m Long Nb₃ Sn Low-β Quadrupole Magnets for the Hi-Lumi LHC Upgrade

Journal Article · 01 June 2020 · IEEE Transactions on Applied Superconductivity

DOI: https://doi.org/10.1109/TASC.2020.2972210 · OSTI ID:1606211

Cheng, Daniel W.  ^[1]; Ambrosio, Giorgio  ^[2]; Anderssen, Eric C.  ^[1]; Ferracin, Paolo  ^[3]; Grosclaude, Philippe  ^[3]; Guinchard, Michael ^[3]; Muratore, Joseph  ^[4]; Pan, Heng  ^[1]; Prestemon, Soren O.  ^[1]; Vallone, Giorgio ^[1]

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1. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
2. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
3. European Organization for Nuclear Research (CERN), Geneva (Switzerland)
4. Brookhaven National Lab. (BNL), Upton, NY (United States)

The U.S. High-Luminosity LHC Accelerator Upgrade Project (HL-LHC AUP) team is collaborating with CERN in the design and fabrication of the first 4.5 m long MQXFA magnets, a 150 mm aperture high-field Nb3Sn quadrupole magnet that uses the aluminum shell-based bladder-and-key technology. The first two prototype magnets, MQXFAP1 and MQXFAP2, were assem-bled and tested while the first pre-series structure (MQXFA03) was in fabrication. This paper summarizes the mechanical perfor-mance of these prototype structures based on the comparison of measured strain gauge data with finite element model analyses from all load steps to powering. The MQXFAP1 magnet almost reached ultimate current before a short to ground was detected and the test was stopped. The MQXFAP2 magnet experienced a low training performance due to a fractured aluminum shell. MQXFAP1b was rebuilt with a new replacement coil, but an old coil limited the magnet from achieving the ultimate current. The mitigations and analyses of these prototype magnets are discussed in the context of the transition to pre-series production.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY (United States); Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP)
• Grant/Contract Number: AC02-07CH11359
• OSTI ID: 1606211
• Report Number(s): FERMILAB-PUB-20-117-TD; oai:inspirehep.net:1787685; TRN: US2104484
• Journal Information: IEEE Transactions on Applied Superconductivity, Vol. 30, Issue 4; ISSN 1051-8223
• Publisher: Institute of Electrical and Electronics Engineers (IEEE)Copyright Statement
• Country of Publication: United States
• Language: English