Status of CIEMAT work on PETS

The goal of the present CLIC Test Facility (CTF3) is to demonstrate the technical feasibility of the CLIC scheme, where the RF power extracted from the drive beam is used to accelerate the main beam. Several prototypes of the RF power extractor so-called PETS (Power Extraction and Transfer Structure) have been developed at CIEMAT for this facility. The first device was embedded in a steel vacuum tank and installed at the Test Beam Line (TBL), whose aim is to prove the beam stability during deceleration and power extraction. Presently, CERN and CIEMAT share the responsibility to build eight additional PETS for TBL. Finally, in the framework of EuCARD (European Coordination for Accelerator Research and Development) collaboration, a new PETS configuration is presently under engineering design at CIEMAT. It is based on a compact concept developed at CERN. This device will be installed in the Test Module at CTF3, in a similar configuration to that of the final two-beam scheme acceleration of CLIC. This paper describes the PETS prototype fabrication techniques used at CIEMAT, with particular attention to the production of the long copper rods which induce the RF generation and the welding and assembly procedures. The characterization of the devices with low RF power and the first tests with beam are also described. ► Correct PETS performance is essential to show CLIC technical feasibility. ► Assembly and production of OFE copper pieces with extreme precision is proved. ► PETS design is evolving towards a compact structure with integrated vacuum tank.