Civil Engineering update - alignment configuration Infrastructure & Operation Meeting 36 – 12th April 2017 Civil Engineering update - alignment configuration

John Osborne, Joanna Stanyard, Matthew Stuart (CERN-SMB-SE) Machine Layout John Osborne, Joanna Stanyard, Matthew Stuart (CERN-SMB-SE)

John Osborne, Joanna Stanyard, Matthew Stuart (CERN-SMB-SE) Previous versions Rome 2016: Intersecting v non-intersecting 100 km options considered Intersecting option main challenges: 7.8 km tunnelling through Jura limestone, deep shafts at F,G,H Non-intersecting option main challenges: 11.6 km tunnelling through pre-alps geology with very high overburdens. August 2016: V2, V3, V4 introduced in comparison to Intersecting option (V1) V2, V3, V4 were all considered improvements to V1 V4 chosen at this point to develop. March/April 2017: 4 different variations of V4 assessed (different arc lengths) Variation 2 of V4 chosen to be developed. Different positions of this alignment currently under consideration. John Osborne, Joanna Stanyard, Matthew Stuart (CERN-SMB-SE)

John Osborne, Joanna Stanyard, Matthew Stuart (CERN-SMB-SE) Evaluation considerations % Molasse % Limestone % Moraines Number of sectors passing through limestone Total shaft length (m) Geology of shafts and caverns Number of shafts over 400m Shaft positions and if there are any reasonable alternatives John Osborne, Joanna Stanyard, Matthew Stuart (CERN-SMB-SE)

John Osborne, Joanna Stanyard, Matthew Stuart (CERN-SMB-SE) Options 1 and 2 – same position, different depths Pros Cons Option 1 Reasonable geology along alignment (93.2% molasse). Tunnel very close to Jura limestone and does not avoid moraines under lake. Shaft F = 545 m. Shaft L located very near protected area in Dardagny. Shaft E to be excavated in moraines. Option 2 Total shaft length 2656 m (reduced from 2919 m option 1) Only 1 sector in limestone Shallower and hence depth to LHC and SPS reduced. Passes through moraines under land. Shaft F = 551 m Option 1 Option 2 John Osborne, Joanna Stanyard, Matthew Stuart (CERN-SMB-SE)

John Osborne, Joanna Stanyard, Matthew Stuart (CERN-SMB-SE) Option 3 – option 2 rotated 10 degrees anti-clockwise Pros Cons Option 3 Shafts A and B in reasonable positions near CERN. Shaft E shifted out of moraines Shaft I completely in limestone and 575 m deep. 2 sectors containing limestone. 2 shafts in sensitive locations in Switzerland. Total shaft length 3451m. Passes through Moraine under lake Option 3 John Osborne, Joanna Stanyard, Matthew Stuart (CERN-SMB-SE)

John Osborne, Joanna Stanyard, Matthew Stuart (CERN-SMB-SE) Option 4 – A full intersecting version Pros Cons Option 4 F is shallower than previous options 422m. B moves away from difficult position near the airport. Passes through significant length of Jura limestone. At least two sectors of limestone excavation. Total shaft length not reduced from option 1, 3034 m. Option 4 John Osborne, Joanna Stanyard, Matthew Stuart (CERN-SMB-SE)

John Osborne, Joanna Stanyard, Matthew Stuart (CERN-SMB-SE) Option 5 – small adjustment to option 2 Pros Cons Option 5 Total Shaft length 2593 m. Shaft F reduced from 551 m (option 2), to 492 m. Only 1 sector containing limestone. Reasonable geology along alignment (91.7% molasse). Passes through moraines under the lake. Shaft E excavated though moraines. Option 5 John Osborne, Joanna Stanyard, Matthew Stuart (CERN-SMB-SE)

John Osborne, Joanna Stanyard, Matthew Stuart (CERN-SMB-SE) 3D schematic updates Currently in work: Additional shaft at each experimental point connecting into experimental cavern. Beam dumps moving to end of straight section. Alcoves to be shown the whole way around the ring. John Osborne, Joanna Stanyard, Matthew Stuart (CERN-SMB-SE)