Design of High-Precision lifting system for the HL-LHC Heavy Components in the interaction region

Given the high radiation level and the tight alignment tolerances, the HL-LHC interaction region components are designed to be realigned remotely using motorized supporting jacks, as human interventions in these zones must be limited to the strict minimum. A position adjustment system will allow a vertical and horizontal displacement of each jack support by at least +/- 2.5 mm with a resolution of less than 10 μm. The weight of the supported elements, up to 170 kN and transverse loads reaching 30 kN, will have to be remotely moved by means of mechanical actuators. The system will be exposed to a cumulated radiation dose of up to 2 MGy during the 15 years of lifetime. To comply with these requirements, an extensive design effort has been initiated at CERN to study the possible system layouts. This includes the prototyping of various solutions, studying subsystems through dedicated test setups and using simulations to obtain a clear understanding of the mechanical principles at play. This paper reports on the work undertaken to design the high-precision lifting system, the various mechanical analysis carried out, and their main outcome. It reviews the proposed solutions and their expected alignment performance