CLIC accelerator modules under construction at CERN

The Compact LInear Collider (CLIC) study is dedicated to the design of an electron-positron (e- e+) linear accelerator, colliding particle beams at the energy of 3 TeV. The CLIC required luminosity can be reached with powerful particle beams (14 MW each) colliding with extremely small dimensions and high beam stability at the interaction point. The accelerated particle beams must have dimensions of 45 nm in the horizontal plane and 1 nm in the vertical plane. CLIC relies upon a novel two-beam acceleration concept in which the Radio Frequency (RF) power is extracted from a low energy but high-intensity particle beam, called Drive Beam (DB), and transferred to a parallel high energy accelerating particle beam, called Main Beam (MB). The extraction and transfer of the RF power is achieved by the Power Extraction and Transfer Structures (PETS) and the particle beam acceleration is achieved with high precision RF-Accelerating Structures (AS), operating at 11.9942 GHz with an accelerating gradient of 100 MV/m, which are mounted and pre-aligned on specially developed supports, so-called girders. The PETS are linked to the AS via a waveguide network, including several RF components. The two linacs are filled by two-beam modules, the smallest repetitive unit of the collider, housing all the main RF components and focusing magnets. The overall length of each linac is about 21 km. A few CLIC two-beam module types were defined, according to the optics requirements for the MB. Quadrupole focusing magnets also need to be integrated, and have high stability requirements (1 nm at above 1 Hz) and their own support.