Fermilab, Batavia, Illinois, USA
CERN, Geneva, Switzerland
FNAL and CERN magnet groups are developing a twin-aperture Nb3Sn 11 T dipole suitable for installation in the LHC to provide room for additional collimators in the dispersion suppressor (DS) areas. Two of these magnets with a collimator in between will replace one regular MB dipole. A single-aperture 2-m long dipole demonstrator and two 1-m long dipole models have been assembled and tested at FNAL in 2012-2014. The 1 m long collared coils were then assembled into the twin-aperture configuration and tested in 2015. The first magnet test was focused on the quench performance of twin-aperture magnet configuration including magnet training, ramp rate sensitivity and temperature dependence of magnet quench current. In the second test performed in July 2016 field quality in one of the two magnet apertures has been measured and compared with the data for the single-aperture models. These results are reported and discussed in this paper.
ANL, Argonne, Illinois, USA
Fermilab, Batavia, Illinois, USA
BNL, Upton, Long Island, New York, USA
Extensive prototyping of storage ring magnets is ongoing at the Advanced Photon Source (APS) in support of the APS Multi-Bend Achromat upgrade (APS-U) project. As part of the R&D activities 4 quadrupole magnets with slightly different geometries and pole tip materials, and one sextupole magnet with vanadium permendur pole tips were designed, built and tested. Magnets were measured individually using a rotating coil and a Hall probe for detailed mapping of the magnetic field. Magnets were then assembled and aligned relative to each other on a steel support plate and concrete plinth using precision machined surfaces to gain experience with the alignment method chosen for the APS-U storage ring magnets. The required alignment of magnets on a common support structure is 30 micron rms. Measurements of magnetic field quality, strength and magnet alignment after subjecting the magnets and assemblies to different tests will be presented.
