First operating experiences of beam position monitors in the TESLA Test Facility Linac

Different types of monitors were installed in the TESLA Test Facility Linac to measure the beam position. At each superconducting quadrupole, the transverse beam position will be measured with a resolution of better than 10 mu m, using a cylindrical cavity excited in the TM110-mode by an off-center beam. In addition, two 'warm' cavities working at room temperature were built for the Injector I and the Bunch Compressor. The amplitude of the TM110-mode and its phase are measured in a homodyne receiver. For the experimental area, stripline monitors having a resolution of better than 100 mu m were built, tested and installed. The averaged position of the whole bunch train of Injector I is measured in a narrowband receiver using the amplitude-to-phase conversion. This paper summarizes the designs, cold tests and first operating experiences of both monitor types.