Field measurement of Fermilab-built quadrupole magnets for the LHC interaction regions

Superconducting low-beta quadrupole magnets for the interaction regions of the Large Hadron Collider have been developed by the US-LHC Accelerator Project. These 70 mm bore 5.5 m quadrupole magnets are intended to operate in superfluid helium at 1.9 K with a nominal field gradient of 215 T/m. Fabrication and testing of these magnets has begun at Fermilab. Magnetic field measurements of the first magnets produced are described and compared with results from prototype magnets as well as with requirements set by machine performance studies.