MEASURING THE BUNCH FREQUENCY MULTIPLICATION AT CTF3

The CLIC Test Facility 3 (CTF3) is being built and com-missioned by an international collaboration to test the fea-sibility of the proposed Compact Linear Collider (CLIC) drive beam generation scheme. Central to this scheme is the use of RF deflectors to inject bunches into a delay loop and a combiner ring, in order to transform the initial bunch frequency of 1.5 GHz from the linac to a final bunch fre-quency of 12 GHz. The optimization procedure relies on several steps. The active length of each ring is carefully adjusted to within less than millimeter accuracy using a wiggler magnet. The transverse optics of the machine must be set up in a way to ensure beam isochronicity. Diagnos-tics based on optical Streak camera and RF power mea-surements have been designed to measure the longitudinal behavior of the beam during the combination. This paper presents their performance and recent measurements