Evaluation of Field Quality for Seperation Dipoles and Matching Section Quadrupoles for the LHC High Luminosity Lattice at Collision Energy

The high luminosity upgrade of the LHC lattice (HLLHC) requires new larger aperture magnets to be installed in the low-beta interaction regions (IRs). These include Nb$_{3}$Sn superconducting (SC) inner triplet (IT) quadrupoles, Nb-Ti SC separation dipoles D1 and D2, and SC Q4 quadrupoles [1, 2, 3, 4]. The upgrade significantly reduces the β* functions at these IRs at collision energy [5]. Consequently, beta functions and beam size in these magnets will increase, thus requiring a larger aperture. The high beta functions also increase the impact of high order field errors in these magnets on dynamic aperture (DA). Therefore, to maintain an acceptable DA, the field quality in the new magnets needs to be specified. Since the error effects at collision are dominated by the triplets, their field quality was specified first [6]. Next, the field errors were added to the D1, D2 dipoles and Q4, Q5 matching quadrupoles while keeping the IT errors to specifications. The impact of these errors on DA was determined in tracking simulations using SixTrack [7]. First evaluation of the field quality in the D1, D2, Q4 and Q5 magnets is presented.