Status of the TESLA Test Facility (TTF)

Within the frame of an international collaboration the TESLA Test Facility has been established at DESY to explore the technology needed for a large s uperconducting linear collider. The key activities are: to develop quality control of Nb material and fabrication methods for high gradient resonators ; to apply and optimise preparation techniques like ultraclean chemistry, h igh pressure water cleaning, high temperature firing and high RF power proc essing; to develop necessary but critical auxiliary components like coupler s, tuners and highly efficient klystrons; to design and test cryostats bein g optimised for a very long superconducting accelerator unit; and to build and operate a 1 GeV superconducting test linac. Up to now 23 nine-cell cavi ties have been measured, the highest gradient being 28.5 MV/m. The gun, cap ture section and the first 8 cavity accelerating unit of the superconductin g linac have been put to operation. Details of cavity and component tests a s well as experience of the first linac operation are presented.