Summary of the Persistent Current Effect Measurements in Nb3Sn and NbTi Accelerator Magnets at Fermilab

In the past ten years, Fermilab has been executing an intensive R&D program on accelerator magnets based on Nb
₃
Sn superconductor technology. This R&D effort includes dipole and quadrupole models for different programs, such as LARP and 11 T dipoles for the LHC high-luminosity upgrade. Before the Nb
₃
Sn R&D program, Fermilab was involved in the production of the low-beta quadrupole magnets for LHC based on the NbTi superconductor. Additionally, during the 2003-2005 campaign to optimize the operation of the Tevatron, a large number of Tevatron magnets were remeasured. As a result of this field analysis, a systematic study of the persistent current decay and snapback effect in these magnets was performed. This paper summarizes the result of this study and presents a comparison between Nb
₃
Sn and NbTi dipoles and quadrupoles.