The CLIC Test Facility 3 (CTF3) is primarily a scaled version of the CLIC drive beam complex. It produces the high-current drive beam that generates the 12 GHz RF power for the CLIC accelerating structures.

CTF3 first accelerates a 4 A beam up to 120 MeV, in a fully loaded linac with more than 95% efficiency. A delay loop and one combiner ring subsequently compress the beam current up 28 A. The high-current beam can then be sent in the CLIC experimental area (CLEX) where it can be decelerated to extract 12 GHz RF power to be used for high gradient acceleration. In the same area a 200 MeV injector (CALIFES) generates a Probe Beam for two-beam experiments.

CTF3 has successfully demonstrated drive beam generation, the production of the CLIC RF power, and two-beam acceleration up to a gradient of 145 MeV/m, well above the 100 MeV/m nominal for CLIC. It will continue to operate up to the end of 2016 to address further system tests and perform more detailed studies.