Calibration, testing, commissioning and first data of ALFA at LHC

The tracking detectors are made of scintillating square fibers read out by MultiAnode PhotoMutiplier Tubes, MAPMTs, with custom made electronics. The gain of the MAPMT channels has been equalized and the average light yield of scintillating fibers determined before installation in the LHC. Also reflections on the Roman Pot windows have been observed and the window has been blackened to reduce the effect. The ALFA detectors are currently being commissioned at ATLAS/LHC and the first particles have been observed in the detectors.