First Field Measurements of the 15 T Nb3Sn Dipole Demonstrator MDPCT1

Within the US Magnet Development Program (MDP), a 15 T Nb3Sn dipole was developed to demonstrate a possible magnet design for a post-LHC proton-proton Collider. The magnet design is based on 60 mm aperture 4-layer shell-type coils, graded between the inner and outer layers to maximize magnet performance. Magnet coils are surrounded by vertically split thick iron laminations, connected by aluminum I-clamps, and a thick stainless-steel skin. The magnet coils were preloaded to achieve 14 T in the first test. The magnet was tested at the Vertical Magnet Test Facility (VMTF) at Fermilab. This paper reports the first results of magnetic measurements of the 15 T Nb3Sn dipole demonstrator, including dipole strength, geometrical harmonics, coil magnetization and iron saturation effects. At the maximum quench current of 9742 A we obtained a dipole strength of 14.13 T.