Macroassembly and performance of the ATLAS SCT barrels

The ATLAS semiconductor tracker (SCT) is a major component of the inner detector being built for the ATLAS experiment, one of two general-purpose experiments for the forthcoming Large Hadron Collider (LHC) at the CERN laboratory. The SCT consists of four barrel cylinders and 18 end-cap discs covered with 4088 radiation hard silicon detector modules. The macroassembly of the SCT barrels has recently been finished and the last barrel was sent to CERN on 24th August, 2005. The mounted modules were electrically tested during and after the macroassembly using a subset of the data acquisition system and power supply hardware that will be used in the final experiment. More than 99.7% of all channels of the SCT barrels are fully functional and no serious problems potentially degrading the SCT performance have been encountered during the barrel assembly process.