Magnetic field measurements of the prototype LHC-IR MQXA at 1.9 K

KEK has developed a prototype of the 6.6 m long MQXA quadrupole for the LHC interaction region. After the first cool-down to 1.9 K, the magnetic field measurements were performed. The prototype could produce a field gradient of 215 T/m corresponding to the operating point of the LHC flat top. The field quality of the magnet was sufficiently good to satisfy the requirement of the accelerator beam optics.