The FE-I4 telescope for particle tracking in testbeam experiments

A testbeam telescope, based on ATLAS IBL silicon pixel modules, has been built. It comprises six planes of planar silicon sensors with 250 × 50 μ m² pitch, read out by ATLAS FE-I4 chips. In the CERN SPS H8 beamline (180 GeV π⁺) a resolution of better than 8 × 12 μm² at the position of the device under test was achieved. The telescope reached a trigger rate of 6 kHz with two measured devices. It is mainly designed for studies using FE-I4 based prototypes, but has also been successfully run with independent DAQ systems. Specialised trigger schemes ensure data synchronisation between these external devices and the telescope. A region-of-interest trigger can be formed by setting masks on the first and the last pixel sensor planes. The setup infrastructure provides centrally controlled and monitored high and low voltage power supplies, silicon oil cooling, temperature and humidity sensors and movable stages.