Optics and Layout Solutions for HL-LHC with Large Aperture Nb$_{3}$Sn and NB-TI Inner Triplets

The LHC Upgrade studies, formalized into the High- Luminosity LHC (HL-LHC) project, relies on the feasibility of very low , and in particular on a novel achromatic squeezing mechanism, the ATS scheme [1] which is presently under test in the LHC. We present two optics and layout scenarios for the HL-LHC using the ATS scheme, one based on Nb$_{3}$Sn triplet quadrupoles with a coil aperture compatible with an operational gradient of 150 T/m, and a backup scenario based on the NbTi technology compatible with an operational gradient of 100 T/m. The solution obtained are analyzed in terms of reach (flat or round), mechanical acceptance, optics flexibility, chromatic properties, and dynamic aperture in the presence of the large -beating waves induced in the arcs by the ATS scheme