The GBT-based readout concept for the silicon tracking system of the CBM experiment

This paper presents the readout concept for the Silicon Tracking System (STS) of the CBM experiment at FAIR, which is designed to handle interaction rates up to 10 MHz with hundreds of tracks in fixed target heavy ion collisions of up to 35 AGeV. For data readout from the frontend electronics located close to the silicon strip sensors, the radiation tolerant Gigabit Transceiver ASICs (GBTx) and Versatile Link optical modules developed at CERN are used. The usage of these devices in the STS readout and the readout concept from the frontend electronics to the GBT based STS readout board (ROB) are detailed. Special emphasis is put on the implementation of the interface between the frontend boards (FEBs) and the ROB layer.