Analysis of the Mechanical Performance of the 4.2-m-Long MQXFA Magnets for the Hi-Lumi LHC Upgrade

Under the U.S. High Luminosity LHC Accelerator Upgrade Project (HL-LHC AUP), 150 mm bore, high-field Nb 3 Sn low-β MQXFA quadrupole magnets are being fabricated, assembled and tested, in context of CERN Hi-Luminosity (HL-LHC) upgrade. These have 4.2 m magnetic length 4.56 long iron yoke. To date, eight been tested. One additionally underwent a successful endurance test with 40 triggered quenches, two did not perform as expected. This work summarizes for first time available strain gauge data from identical tested magnets, focusing on test, possible cause underperformance that pass vertical test. We applied methods to prevent this happening future which shown be effective last magnets.