Chapter 7: R&D programmes oriented towards specific future facilities: Section 7.3: CLIC-specific R&D programme

The Compact Linear Collider (CLIC) is a multi-TeV high-luminosity linear e$^{+}$e$^{−}$ collider under development by the CLIC accelerator collaboration, hosted by CERN. The CLIC accelerator has been optimised for three energy stages at centre-of-mass energies 380 GeV, 1.5 TeV and 3 TeV. CLIC uses a novel two-beam acceleration technique, with normal-conducting accelerating structures operating in the range of 70 MV/m to 100 MV/m.This section reports on the accelerator design, technology developments, system tests and beam tests for the CLIC accelerator study. Large-scale CLIC-specific beam tests have taken place, for example, at the CLIC Test Facility CTF3 at CERN, at the Accelerator Test Facility ATF2 at KEK, at the FACET facility at SLAC and at the FERMI facility in Trieste. Crucial experience also emanates from the expanding field of Free Electron Laser (FEL) linacs and recent-generation light sources as well as medical applications. Together they demonstrate that all implications of the CLIC design parameters are well understood and reproducible in beam tests and prove that the CLIC performance goals are realistic. The implementation of CLIC near CERN has been studied in detail. Focusing on a staged approach, starting at 380 GeV, this includes civil engineering aspects, electrical networks, cooling and ventilation, installation scheduling, transport, and safety aspects. All CLIC studies have put emphasis on optimising cost and energy efficiency, and the resulting power and cost estimates are reported.