Particle accelerator projects, ILC, CLIC, FCC, CERN, Geneva, Switzerland.

For future particle accelerator facilities a study was conducted on international level. It comprises the concept, to accelerate electrons, positrons as well as protons to very high energies in the range of terra electron volts and to bring them to collision.

Overview Project:

  • Particle accelerator of superlative with energies in the multi digit terra volt region.
  • 2 linear accelerators ILC and CLIC for collisions with electrons and their anti-particles positrons (FCC-ee) by accelerator tunnel 30 and 48 km long, various shafts an experimental caverns.
  • 1 ring shaped accelerator tunnel 80 – 100 km long for collisions with hadrons (FCC-hh), hadrons-leptons (FCC-he) and Leptons (FCC-ee), various shafts and experimental caverns.
  • The accelerators serve for the physical investigation of the building parts of the elementary particles, which are generated by collisions with very high energy.

Project description

Complex interrelated system of subsurface constructions for supply and acceleration of electrons/positrons (ILC, CLIC) and protons (FCC). The big challenge was the realization of the ideas and related boundary conditions from nuclear physics in an interrelated system of subsurface buildings, which can be built at reasonable cost.

1) ILC – schematic view; 2) CLIC – schematic view and geological situation; 3)ILC – 3D-view of area around detector cavern; 4) Electron / positron feeding into the main tunnel.

Special requirements:

  • Groundwater saturated moraine and formation water from karst of the Jura foothills in the south.
  • Measures to keep interruptions in operation at a minimum in order to ensure a continuous investigation of the particle collisions at the detector sites.
  • Provision of a considerable number of annex buildings such as particle beam stoppers /energy centrals etc. accessed from the accelerator tunnel under construction.
  • Accelerator tunnel "laser straight“.

Deep shafts, big caverns and long machine driven headings with a considerable number of annex-buildings like caverns, turning loops etc. All building elements were designed after the ideas and conditions of the later users with consideration of the local geological conditions and assessed in respect to their interconnection with the adjacent elements and their counter action to each other.

1) CLIC – UTRC cavern, drive beam loop & beam dump; 2) Scheme of cavern with interaction areas; 3) CLIC – Scheme for 3 TeV extension; 4) Scheme / Installations for particle accelerator.

Special requirements:

  • Suitable construction methods for sealing of more than 50 m deep construction pits for building of the shafts in the water saturated moraine.
  • Approximate determination of sealing thickness for compensation of surface loads for pair wise located detector caverns (more than 30 m wide and 40 m high).
  • Optimization of requirements for tunnel construction (tunnel boring and reinforcement) for the construction of the many annex buildings.

Integration of all subsurface and surface buildings under consideration of constructional, temporal, economical as well as ecological aspects. For the establishment of a cost estimate and the construction program all elements of the accelerator were integrated in such a way, that a realistic building process is feasible without encountering reciprocal restrictions.

1) ILC – work program for subsurface constructions; 2) Concept for fire prevention; 3) CLIC Scheme of the entire building complex; 4) CLIC – typical cross-section after installation.

Special requirements:

  • Planning of the building process under consideration of „flexible“ boundary conditions as a result of the latest results from the ongoing scientific investigations.
  • Suitable shaft dimensions and installations to fulfil the logistic tasks for the construction operation and for the necessary installation of the accelerator equipment.
  • Side gallery in Jura formation for accomplishment of high formation water ingress in karstic areas.