Calibration and alignment of the SPD detector with cosmic rays and first LHC collisions

The calibration of the SPD response is essential for the correct performance of the detector. The SPD features a binary output readout, so it requires a dedicate calibration procedure based on scans of the threshold value. The LHCb commissioning with cosmic rays allowed to validate the pre-calibration parameters obtained in the laboratory and to prepare the detector for providing the first minimum bias triggers for LHCb. The fine calibration has been done with tracks from LHC collisions, allowing to obtain the design precision in the threshold settings. This note describes the method used for the calibration, base on the fit of the efficiency as a function of the threshold value. The results obtained from the calibration to be applied in 2011 data taking are discussed. The first results on the alignment of the detector with respect to the trackers with 2010 data are also given.