Construction and Cold Test of the First Superferric Corrector Magnet for the LHC Luminosity Upgrade

INFN is developing at LASA lab (INFN Milano, Italy) the prototypes of five corrector magnets, from skew quadrupole to dodecapole, which will equip the high-luminosity interaction regions of the High Luminosity-LHC. These magnets are based on a superferric design, which allows a relatively simple, modular, and easy to construct magnet. This activity takes place within the framework of a collaboration agreement between CERN and INFN. The first prototype, a sextupole, has been assembled in early 2016. We present here the results of the cold test, including the training performed at 4.2 K and the qualification at 2.2 K. We report also on the overall experience gained during its construction and test. An important aspect is represented by the analysis of the manufacturing tolerances of the mechanical pieces and the alignment accuracy achieved. These results will serve as a basis for the design of the next magnets, the octupole, and the decapole. Other important results concern the cold performance of the coil-to-coil electrical joints (especially critical in a magnet with a large number of coils), dynamic inductance measurements and quench studies.