Quench Performance and Field Quality of FNAL Twin-Aperture 11 T Nb3Sn Dipole Model for LHC Upgrades

A 2-m-long single-aperture dipole demonstrator and two 1-m-long single-aperture models based on Nb
₃
Sn superconductor have been built and tested at FNAL. The two 1-m-long collared coils were then assembled in a twin-aperture Nb
₃
Sn dipole demonstrator compatible with the LHC main dipole and tested in two thermal cycles. This paper summarizes the quench performance of the FNAL twin-aperture Nb
₃
Sn 11 T dipole in the temperature range of 1.9-4.5 K. The results of magnetic measurements for one of the two apertures are also presented. Test results are compared to the performance of coils in a single-aperture configuration. A summary of quench propagation studies in both apertures is given.