Assembly, construction and testing of the ALICE silicon pixel detector

The Silicon Pixel Detector (SPD) is the innermost detector of the ALICE experimental apparatus. ALICE is the CERN LHC experiment dedicated to the study of ultra-relativistic heavy ion collisions, furthermore ALICE will contribute to the proton–proton physics programme. D is based on hybrid SPDs assembled in 120 modules (half-staves). The half-staves are mounted on 10 low-mass carbon fibre sectors arranged in two barrel layers placed at 3.9 and 7.6 cm from the colliding beams. The total SPD silicon surface is 0.2 m2. D assembly procedure and the current status of the construction are overviewed.