INSTALLATION OF THE LHC LONG STRAIGHT SECTIONS (LSS)

The LHC long straight sections (LSS) serve as experimental or utility insertions. There are two high luminosity experimental insertions located at Point 1 and 5 and two more experimental insertions at Point 2 and 8 which also contain the injection systems. The beams only cross at these four locations and are focused by superconducting low-beta triplets. Insertions 3 and 7 each contain two collimation systems. Insertion 4 contains two RF systems. Insertion 6 contains the beam dumping system. The installation of the LSS is a challenge due to the compact layout that characterise these areas and the difficulties related to the underground work mainly in zones of restricted access. Specific devices are required for handling and installing various heavy and voluminous elements. This paper reviews the installation scenarios, describes the sequences presently planned and highlights the potential problem areas. The particular case of sector 7-8 where the LSS elements will be installed in parallel with the cryogenic distribution line (QRL) is used as an example of a ‘rapid' installation scheme to illustrate how resources are used. The consequences of possible shortcuts are also mentioned.