Performance of the beam position monitor system of the final focus test beam

The Beam Position Monitor (BPM) system for the Final Focus Test Beam (FFTB) at SLAC is designed to meet challenging specifications in the areas of single-pulse resolution, ab initio installation accuracy, and time-stability of BPM electrical centroids. We review the tolerances on these quantities and the technical choices made to achieve same, and detail the results of several studies of the actual performance of the system. These results are then related to the BPM system requirements for a future high-energy e+e− linear collider.