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Title: Fabrication and Analysis of 150-mm-Aperture Nb 3Sn MQXF Coils

The U.S. LHC Accelerator Research Program (LARP) and CERN are combining efforts for the HiLumi-LHC upgrade to design and fabricate 150-mm-aperture, interaction region quadrupoles with a nominal gradient of 130 T/m using Nb 3Sn. To successfully produce the necessary long MQXF triplets, the HiLumi-LHC collaboration is systematically reducing risk and design modification by heavily relying upon the experience gained from the successful 120-mm-aperture LARP HQ program. First generation MQXF short (MQXFS) coils were predominately a scaling up of the HQ quadrupole design allowing comparable cable expansion during Nb 3Sn formation heat treatment and increased insulation fraction for electrical robustness. A total of 13 first generation MQXFS coils were fabricated between LARP and CERN. Systematic differences in coil size, coil alignment symmetry, and coil length contraction during heat treatment are observed and likely due to slight variances in tooling and insulation/cable systems. Analysis of coil cross sections indicate that field-shaping wedges and adjacent coil turns are systematically displaced from the nominal location and the cable is expanding less than nominally designed. Lastly, a second generation MQXF coil design seeks to correct the expansion and displacement discrepancies by increasing insulation and adding adjustable shims at the coil pole and midplanes to correctmore » allowed magnetic field harmonics.« less
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  1. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
  2. Brookhaven National Lab. (BNL), Upton, NY (United States)
  3. European Organization for Nuclear Research (CERN), Geneva (Switzerland)
  4. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Publication Date:
Report Number(s):
BNL-111686-2015-JA; FERMILAB-PUB-15-358-TD
Journal ID: ISSN 1051-8223; KA1502010
Grant/Contract Number:
SC00112704; AC02-05CH11231; AC02-07CH11259; AC02-98CH10886; AC02-07CH11359
Accepted Manuscript
Journal Name:
IEEE Transactions on Applied Superconductivity
Additional Journal Information:
Journal Volume: 26; Journal Issue: 4; Journal ID: ISSN 1051-8223
Institute of Electrical and Electronics Engineers (IEEE)
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Contributing Orgs:
Country of Publication:
United States
43 PARTICLE ACCELERATORS; NB₃Sn Magnet; Superconducting Accelerator Magnets; Low-beta Quadrupole; High Luminosity LHC; Nb3Sn magnet; superconducting accelerator magnets; low-beta quadrupole; high luminosity LHC; coils; superconducting cables; superconducting magnets; cable insulation; niobium-tin; apertures
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1245372; OSTI ID: 1456943