LARP Long Quadrupole: A “Long” Step Toward an LHC Luminosity Upgrade with Nb₃Sn Magnets

Giorgio Ambrosio

Fermilab

The beginning of the development of Nb₃Sn magnets for particle accelerators goes back to the 1960’s. But only very recently has this development begun to face the challenges of fabricating Nb₃Sn magnets which can meet the requirements of modern particle accelerators. LARP (the LHC Accelerator Research Program) is leading this effort focusing on long models of the Interaction Region quadrupoles for a possible luminosity upgrade of the Large Hadron Collider. A major milestone in this development is to test, by the end of 2009, 4m-long quadrupole models, which will be the first Nb₃Sn accelerator-type magnets approaching the length of real accelerator magnets. The Long Quadrupoles (LQ) are “Proof-of-Principle” magnets which are to demonstrate that Nb₃Sn technology is sufficiently mature for use in high energy particle accelerators. Their design is based on the LARP Technological Quadrupole (TQ) models, under development at FNAL and LBNL, which have design gradients higher than 200 T/m and an aperture of 90 mm. Several challenges must be addressed for the successful fabrication of long Nb₃Sn coils and magnets. These challenges and the solutions adopted will be presented together with the main features of the LQ magnets. Several R&D lines are participating to this effort and their contributions will be also presented.