Challenges in the design of linear accelerator tunnels and services

Studies are well underway for the next generation of linear accelerators. The International Linear Collider (ILC) is working towards a maximum collision energy of 1 TeV and the Compact Linear Collider (CLIC) even higher at 3 TeV. Although the accelerating technologies are very different, many similarities can be found between the two projects from a civil engineering and technical services point of view. Both projects would require a site of approximately 50 km in length with stable geological conditions. CERN has been selected as one of the sample sites for the preliminary studies. The aim of this paper is to present the key challenges in the design of civil engineering and technical services such as cooling, ventilation and electricity that need to be overcome to realise such large scale projects in the future.