Electrical test results from ATLAS-SCT end-cap modules

The LHC operating conditions present several challenges to the module performance of the ATLAS Semiconductor Tracker (SCT). This detector consists of four cylindrical barrel layers of silicon strip detectors and of 18 disks in the forward and backward direction. Four dieren t module designs exist, one for the barrel and three (inner, middle and outer) for the rings of the disks. A series of several end-cap module pre-production prototypes of inner, middle and outer types have been built and extensively characterized on single module test benches in the institutes of the collaboration. The scope of this document is to summarize the electrical performance measurements made in laboratory on these end-cap module pre-production prototypes, with special emphasis on the result of electrical tests after irradiation. As summarized in the conclusion, the electrical performance specications are met before irradiation, but are exceeded at 1 fC threshold after an irradiation dose of 1:5:10 14 24 GeV-p/cm 2 , that is a uence corresponding to about half the total dose ATLAS-SCT is foreseen to receive during its life time. After the full uence, the noise occupancy limits could be met by increasing the threshold of the discriminator, with a corresponding expected loss of tracking eciency .