Performance and Reliability Evaluation of Nb$_{\text{3}}$Sn MQXFB Quadrupoles for the HL-LHC at Midpoint Production

At the heart of the High-Luminosity Project (HL-LHC) to upgrade the CERN Large Hadron Collider (LHC), new Nb$_{\text{3}}$Sn superconducting quadrupole magnets will be installed on each side of the ATLAS and CMS experiments. Half of these magnets are built by CERN and are called MQXFB. A total of 12 MQXFB magnets are being constructed for installation: two to be installed in the Inner Triplet (IT) String facility, for systems qualification; four to be installed in the LHC near ATLAS; four to be installed in the LHC near CMS, and two spare magnets. In the last two years, the first seven MQXFB magnets have been tested and qualified up to nominal current in nominal operating conditions. In this paper we present the tests and analyze the magnets’ performance, with emphasis on qualification, non-conformity detection, and reliability evaluation.