New Magnets for the IR: how far are we from the HL-LHC target?

Abstract

Insertion quadrupoles with large aperture and high gradient are required to upgrade the luminosity of the Large Hadron Collider (LHC). The US LHC Accelerator Research Program (LARP) is a collaboration of US DOE National Laboratories aiming at demonstrating the feasibility of Nb$_{3}$Sn magnet technology for this application. Several series of magnets with increasing performance and complexity have been fabricated, with particular emphasis on addressing length scale-up issues. Program results and future directions are discussed