Fabrication and performance of a new high-gradient trim quadrupole for the Fermilab luminosity upgrade

A series of 16 high-gradient trim quadrupole magnets has been designed and built for the Tevatron luminosity upgrade (Fermilab III). These quadrupoles form part of the new-low-beta system for the two interaction regions in the Tevatron Collider. The magnets have been installed in the Tevatron lattice in anticipation of the 1991 collider run. The one-shell design uses a ´cable´ of individually insulated rectangular strands. The cable is overwrapped with Kapton and epoxy impregnated glass tape. The winding, curing, and collaring of the magnet is accomplished in the same manner as Tevatron-like magnets using Rutherford-style cable. Once the magnet is assembled, the five strands are connected in series to achieve high gradient at low current. The required gradient is 0.63 T/cm at 1086 A. The production magnets reached maximum currents of about 1.1 T/cm at 1990 A. The success of this design approach suggests other applications in beam transport where magnets of high performance and low operating cost are required.<>