CLIC test beam facilities: status and results

CERN is studying the feasibility of building a 1 TeV c.m. e+e- linear collider (CLIC) based on 30 GHz accelerating structures and RF power production from a low energy, high intensity drive linac. Two major challenges of the CLIC two-beam scheme are the generation of the high intensity drive beam and the extraction of 30 GHz RF power using transfer structures. Two test facilities are currently being used to study these specific problems. The CLIC Test Facility (CTF) is a purpose-built CERN facility to study the generation of the drive beam by photo-injectors, the generation of 30 GHz RF power, and the testing of components. This facility has produced single bunch charges of 35 nC with a bunch length of 14 ps (FWHH) and up to 76 MW of 30 GHz RF power. It is at present being updated to a 10 m long two-beam test accelerator producing 480 MW of 30 GHz RF peak power and accelerating electron bunches with gradients of 80 MV/m. The FEL Test Facility at CESTA (Bordeaux) is being used to study the generation of the CLIC drive beam by direct bunching at 30 GHz. This facility has recently made the first direct observation of beam bunching by a high power microwave FEL. The status of these two test facilities and the results obtained are given.