LHC luminosity upgrades using closed-in magnets

Among luminosity upgrades presently being considered for the LHC are those that require changes to the insertion optics and magnet systems; changes to the existing inner triplets, quadrupoles placed closer to the detectors, and beam-splitting dipoles placed very close to and even inside the experiments at the high-luminosity interaction regions. The modifications of these magnet systems create challenges for both the experiments and for the magnets themselves. In this paper, we will discuss some of those issues and possible solutions and R&D paths.