Test beam characterization of 3D stc silicon strip detectors

The luminosity upgrade of the LHC to the SLHC will mean a massive increase in radiation levels for the tracking detectors close to the interaction point. The development of ultra-radiation hard silicon detectors is required for the innermost tracking layers. One option for radiation-hard silicon sensors is the 3D technology, where columnar electrodes are etched deep into the silicon bulk. This provides a short charge collection distance, effectively counteracting radiation-induced charge trapping. It also significantly reduces the depletion voltage compared to planar sensor designs. Silicon 3D strip detectors in the single type column (stc) design have been connected to 40 MHz readout electronics from the LHCb experiment, and were placed in a test beam at CERN in Summer 2007. We describe the results from these measurements, and draw conclusions on the maturity of the 3D technology as well as the feasibility to use it for SLHC tracking applications. The test beam has been performed in close cooperation with the University of Glasgow