Plans unveiled in early February by high-energy physicists for a new underground particle accelerator could require 72km of tunnels at a cost of US$1.78bn.
The layout of the research lab will consist of: Twin 31km long, 4.5m diameter tunnels, one that will eventually have particle beams fired along it and the other a service tunnel; a 7km long circular tunnel, 5m in diameter, which will sit in the middle of the parallel tubes to act as a ‘damping ring’; and 13 access shafts.
Three potential sites – in the US, Japan and Europe – are being considered to host the International Linear Collider (ILC), and the host nation will have to foot the bill for the excavations. The sites are: Illinois state not far from Chicago and near the Fermi lab; a plateau site in Japan; and, the Geneva area near CERN.
Geology at the ‘deep-tunnel’ candidate sites is markedly different – dolomite in the US, granite in Japan, and sedimentary rock/sandstone in Europe. The concept plan at this stage considers that nine TBMs can be used in the excavations, five of which would be moved to undertake further drives. Cavern mining at the US, Japan and European sites would be done by drill and blast, NATM and road header, respectively.
Construction work is not anticipated to start until some time in the next decade but following the completion of the ‘reference design’ the engineering design work and value engineering are about to start, and should take two to three years to complete.
Following site selection, funding agreements and detailed design work, it is expected the facility will take seven years to build and fit-out. Civil works are on the critical path of the project programme and its is forecast there will be 450,000m3 of excavated space required to house the facility.
While further design work is done on the ‘deep’ options, International Committee for Future Accelerators (ICFA) plans to investigate a shallow site alternative, either tunnel or cut and cover excavation. The candidate shallow sites are near Hamburg, Germany and Dubna, Russian Federation.
