Luminosity measurement at ATLAS with Roman Pots and scintillating fibre detectors

A scintillating fibre detector has been proposed for the measurement of the absolute luminosity at the interaction point of the ATLAS experiment at LHC. The detector consists of eight identical trackers approached at a distance of about 1 mm from the LHC coasting beams using the well-known “Roman Pot” technique. This contribution describes the design of the detector and of its readout, as well as the performance established during two successful test beam periods at DESY and at CERN, that demonstrated the suitability of the detector for the proposed challenging method of the luminosity measurement.